Lasers

Author: the photonics expert Dr. Rüdiger Paschotta (RP)

Key questions:

• What special properties does laser light have?
• What types of devices are included under the term “laser”?
• What is the basic principle of operation of any laser?
• What enables lasers to form very directed beams with low divergence?
• What factors allow a laser to emit light within a very small bandwidth?
• What methods are used for pulse generation in lasers?
• How can laser light have extremely high optical intensities?
• What are the common types of lasers?
• What are tunable lasers and their benefits?
• Why are narrow-linewidth lasers significant?
• How do superluminescent sources differ from lasers?
• What is parametric amplification in optical parametric generators?
• What are the main safety concerns when working with lasers?
• What are some important applications of laser technology?
• Why are lasers relatively expensive to manufacture?
• What factors are vital for business success in the laser industry?

More questions…

“Laser” (rarely written as l.a.s.e.r.) is an acronym for “Light Amplification by Stimulated Emission of Radiation”, coined in 1957 by the laser pioneer Gordon Gould. Although this original meaning denotes a principle of operation (exploiting stimulated emission from excited atoms or ions), the term is now mostly used for devices generating light based on the laser principle. More specifically, one usually means laser oscillators, but sometimes also includes devices with laser amplifiers, called master oscillator power amplifier (MOPA). An even wider interpretation includes nonlinear devices like optical parametric oscillators and Raman lasers, which also produce laser-like light beams and are usually pumped with a laser, but are strictly speaking not lasers themselves.

Laser technology is at the core of the wider area of photonics, essentially because laser light has a number of very special properties:

• It is usually emitted as a well-directed laser beam which due to its high spatial coherence can propagate over long lengths without much divergence (often limited only by diffraction) and can be focused to very small spots, where a high intensity is achieved.

• It often has a very narrow optical bandwidth (high temporal coherence), whereas e.g. most lamps emit light with a very broad optical spectrum. However, there are also broadband lasers, particularly among ultrafast lasers.

• Laser light may be emitted continuously, or alternatively in the form of short or ultrashort pulses, with pulse durations from microseconds down to a few femtoseconds. The temporal concentration of pulse energy – in addition to the potential of strong spatial confinement in a beam focus – allows for even far higher intensities to be generated. Particularly extreme intensity values are used in high-intensity physics.

These properties, which make laser light very interesting for a range of applications, are to a large extent the consequences of the very high degree of spatial and/or temporal coherence of laser radiation. The articles on laser light and laser applications give more details.

The first laser was a pulsed lamp-pumped ruby laser (a kind of solid-state laser), demonstrated by Theodore Maiman in 1960 [2, 3]. In the same year, the first gas laser (a helium–neon laser [5]) and the first laser diode were made. Before this experimental work, Arthur Schawlow, Charles Hard Townes, Nikolay Basov and Alexander Prokhorov had published ground-breaking theoretical work on the operation principles of lasers, and a microwave amplifier and oscillator (maser) had been developed by Townes' group in 1953. The term “optical maser” (MASER = microwave amplification by stimulated amplification of radiation) was initially used, but later replaced with “laser”.

In laser technology, a wide range of optical components such as laser crystals, laser mirrors, polarizers, Faraday isolators and tunable optical filters are used; see the article on laser optics.

How a Laser Works

Basic Principle of Operation

The basic operation principle of lasers can be well understood by considering how light could be “stored” (maintained) over extended times:

First, we need to somehow spatially confine light such that it cannot escape our apparatus:

• The simplest approach would be using two plane mirrors, reflecting light between each other:

• However, the natural tendency of a light beam to diverge also needs to be counteracted. That can simply be done by using a concave curvature of at least one of the mirrors:

• Here, the spatial profile of the light beam can stay stable constant forever.
• The two remaining problems are (a) to initially get the light into the resonator and (b) to keep the light energy constant despite some unavoidable losses, e.g. by scattering of light on non-perfect mirror surfaces.
• We first solve problem (b) by inserting some light-amplifying medium into the resonator:

• If the light is sufficiently amplified in each path through that “gain medium”, any losses of light (e.g. at the mirrors) can be compensated, so that the optical power in the resonator stays constant.
• The gain medium then also solves problem (a): even if no light is present initially, the gain medium will emit some fluorescence light, some of which has the right direction of propagation to be captured in the resonator. Even if it is weak initially, during many resonator round-trips it can be amplified to a substantial power level.

• The mentioned amplification mechanism is based on stimulated emission of light, which can occur if light hits some electronically excited atoms or ions in the medium. (See the article on stimulated emission for more details.) Depending on the type of laser gain medium, very different mechanisms can be utilized to prepare that excitation which enables stimulated emission. In any case, some kind of energy supply must be provided, since light amplifications means transferring energy to the light. The energy supply may work through electricity, through light, or sometimes with other means such as a beam of fast electrons or chemical energy.

What is still missing for a useful laser is a way to generate a usable output laser beam. This is done by making one of the resonator mirrors only partially reflective, so that part of the circulating light power can escape. Of course, that will substantially increase the losses of the contained light; one will need accordingly stronger amplification in the laser gain medium to maintain laser operation. The higher the achieved gain of the laser gain medium, the more transmission of the output coupler mirror one can afford.

In conclusion, a laser oscillator usually comprises an optical resonator (laser resonator, laser cavity) in which light can circulate (e.g. between two mirrors), and within this resonator a laser gain medium (e.g. a laser crystal), which serves to amplify the light. Below you see an example: an optically pumped solid-state laser:

A laser cannot operate if the gain is smaller than the resonator losses; the device is then below the so-called laser threshold and only emits some weak luminescence light. Significant power output is achieved only for pump powers above the laser threshold, where the gain can reach (or temporarily exceed) the level of the resonator losses. Defects of a laser often raise the threshold to values which cannot be reached, so that laser operation becomes impossible.

If the gain is larger than the losses, the power of the light in the laser resonator rises very rapidly, starting e.g. with low levels of light from fluorescence. Note that the resonator round-trip time is usually very small (e.g. a few nanoseconds, for compact laser types even much less), so that even a small net round-trip gain implies rapid exponential growth of the intracavity power. As high laser powers saturate the gain by extracting energy from the gain medium, the laser power will in the steady state reach a level so that the saturated gain just equals the resonator losses (→ gain clamping). Before reaching this steady state, a laser often undergoes relaxation oscillations (just one aspect of laser dynamics). The threshold pump power is the pump power where the small-signal gain is just sufficient for lasing.

Note that many lasers are not operated continuously, but rather in a pulsed mode of operation, so that laser pulses are emitted. This is explained in a later section.

Directed Emission and Spatial Coherence of Laser Radiation

A high degree of spatial coherence of the laser radiation can be achieved – essentially because the light emission is triggered (stimulated) by the intracavity radiation (i.e., the light circulating in the laser resonator) itself, rather than occurring spontaneously in an uncoordinated fashion. In the stimulated emission process, the laser-active ions are made to emit light in the direction of already existing light, and also with the same optical phase. In effect, the circulating laser light serves to strongly coordinate the emission of many atoms or ions – very much in contrast to what happens in incandescent lamps, for example, where individual atoms emit in a completely uncoordinated manner.

The explained mechanism for coordinated emission is the physical basis for the potential of lasers to form very directed laser beams with low divergence, and for focusing light to very small spots. Quantitatively, this potential can be described via the spatial coherence of laser light.

The resulting amplitude and phase profile of a laser beam is largely determined by the properties of the laser resonator, usually much less by details of the laser gain medium. This is particularly so for lasers which operate on a single transverse mode, which usually leads to the emission of a close to Gaussian beam with nearly perfect beam quality, i.e., highest spatial coherence and optimum potential for focusing.

Emission Wavelengths, Temporal Coherence

Temporal coherence is a different issue, and it has completely different origins. It is related to the optical bandwidth of laser emission (although generally in a non-trivial way).

Most types of lasers can work only with a very restricted choice of emission wavelengths, if not with one emission wavelength only. However, different types can overall cover a very wide range of emission wavelengths from the far light to the ultraviolet light.

Some laser gain media can amplify light only in a narrow spectral range, while others have a large gain bandwidth. Even in the latter case, a laser often (particularly in continuous-wave operation) emits light only within a very small bandwidth, i.e., in a narrow range around a certain wavelength or optical frequency. This is because the conditions are often such that a net zero round-trip gain is possible only for that wavelength, while all other wavelengths exhibit a negative net round-trip gain. As a result, only light within that narrow bandwidth can “survive”, while light at any other wavelengths (even well inside the gain bandwidth) will “die out” without some number of resonator round trips. The emission bandwidth is often orders of magnitude smaller than the gain bandwidth – and particularly small when only a single resonator mode can oscillate (→ single-frequency operation).

A laser may be tuned to the exact wanted wavelength (within the emission region of the gain medium) e.g. by using a tunable intracavity bandpass filter, such as a Lyot filter. Laser gain media like Ti:sapphire and Cr:ZnSe, having a large gain bandwidth, allow wavelength tuning over hundreds of nanometers.

The smaller the emission linewidth (i.e., the narrower the optical spectrum of emitted light), the higher is generally the degree of temporal coherence. A high temporal coherence means that the optical phase stays stable (predictable) over a relatively long time. In extreme cases, the linewidth of a laser can be forced to values below 1 Hz (with certain means of laser stabilization). This is many orders of magnitude below the mean frequency (hundreds of terahertz). Optical clocks involve such highly stabilized lasers.

Interestingly, even ultrashort pulses can exhibit a very high degree of temporal coherence, in that case involving coherence between subsequent pulses in a regular pulse train. This is related to the formation of a frequency comb as the optical spectrum. While the optical spectrum can then overall be very wide, each comb line can be extremely narrow and well defined in frequency.

Generation of Light Pulses

Some lasers are operated in a continuous fashion, whereas others generate pulses, which can be particularly intense. There are various (very different) methods for pulse generation with lasers, allowing the generation of pulses with durations of microseconds, nanoseconds, picoseconds, or even down a few femtoseconds (→ ultrashort pulses from mode-locked lasers). Even far shorter light pulses in the attosecond regime can be generated by sending intense femtosecond pulses into a gas, where high harmonic generation can occur.

Particularly when applying the technique of Q switching, and in conjunction with some pulsed laser amplifiers, a laser medium can accumulate some amount of energy over some “pumping” time to then release it within a much shorter time. This allows one to obtain an output peak power which is orders of magnitude higher than the applied pump power.

Particularly for femtosecond lasers, the emission bandwidth can be very large – even if the instantaneous frequency remains nearly constant during the pulse. That bandwidth is related to the properties of Fourier transforms and can also be explained with considerations on the excitation of oscillators exposed to the light field. In extreme cases, the bandwidth of ultrashort pulses can span about a full octave. Nevertheless, there can strong coherence between subsequently emitted pulses, which is related to the frequency comb structure of the optical spectrum.

Essential Properties of Laser Light

To summarize some already explained aspects, laser light can have very special properties in various respects, which are relevant for many laser applications:

• Its high spatial coherence allows for very directed propagation over large distances and also for tight focusing to small spots. However, not all lasers exhibit perfect beam quality.
• Its temporal coherence, related to its emission bandwidth, is extremely high at least in some cases. However, there are also laser sources with broadband emission and low temporal coherence.
• Laser light may be pulsed, often with short or even extremely short pulse durations, and often with very high peak powers.
• The tight concentration of light both spatially and temporally (in case of laser pulses) can lead to extremely high optical intensities.

Laser Noise

Due to various influences, the output of lasers always contains some noise in properties such as the output power or phase. For pulsed lasers, additional quantities can come into play, for example the timing jitter. For more details, see the article on laser noise.

Types of Lasers

Laser technology is a rather diverse field, utilizing a wide range of very different kinds of laser gain media, optical elements and techniques. Common types of lasers are:

• Semiconductor lasers (mostly laser diodes), electrically (or sometimes optically) pumped, efficiently generating very high output powers (but typically with poor beam quality), or low powers with good spatial properties (e.g. for application in CD and DVD players), or pulses (e.g. for telecom applications) with very high pulse repetition rates. Special types include quantum cascade lasers (for mid-infrared light) and surface-emitting semiconductor lasers (VCSELs, VECSELs and PCSELs). Some of those are also suitable for pulse generation with high powers.

• Solid-state lasers based on ion-doped crystals or glasses (doped insulator lasers), pumped with discharge lamps or laser diodes, generating high output powers, or lower powers with very high beam quality, spectral purity and/or stability (e.g. for measurement purposes), or ultrashort pulses with picosecond or femtosecond durations. Common gain media are Nd:YAG, Nd:YVO₄, Nd:YLF, Nd:glass, Yb:YAG, Yb:glass, Ti:sapphire, Cr:YAG and Cr:LiSAF. A special type of ion-doped glass lasers are:

• Fiber lasers, based on optical glass fibers (containing a waveguide structure) which are doped with some laser-active ions in the fiber core. Fiber lasers can achieve extremely high output powers (up to kilowatts) with high beam quality, allow for widely wavelength-tunable operation, narrow linewidth operation, etc.

• Gas lasers (e.g. helium–neon lasers, CO₂ lasers, argon ion lasers and excimer lasers), based on gases which are typically excited with electrical discharges. Frequently used gases include CO₂, argon, krypton, and gas mixtures such as helium–neon. Common excimers are ArF, KrF, XeF, and F₂. As far as gas molecules are involved in the laser process, such lasers are also called molecular lasers.

Not very common are chemical and nuclear pumped lasers, free electron lasers and X-ray lasers.

Specifically Designed Lasers

Some types of lasers can be specifically be design to achieve high performance in a certain sense. Some examples:

• High-power lasers are optimized for a particularly high output power. Only few laser architectures are suitable for the concept of power scaling of lasers, while many others can at least to some extent be optimized for higher powers (with methods different from scaling).
• Tunable lasers are constructed such that their emission wavelength can be tuned over some region.
• Narrow-linewidth lasers are optimized for a narrow emission bandwidth. Usually, they are single-frequency lasers.

Laser Sources in a Wider Sense

There are some light sources which are not strictly lasers, but are nevertheless often called laser sources:

• In some cases, the term is used for amplifying devices emitting light without an input (excluding seeded amplifiers). An example are X-ray lasers, which are usually superluminescent sources, based on spontaneous emission followed by single-pass amplification. There is then no laser resonator.
• A similar situation occurs for optical parametric generators, where the amplification, however, is not based on stimulated emission; it is parametric amplification based on optical nonlinearities.
• Raman lasers utilize amplification based on stimulated Raman scattering.

Light from such devices can have laser-like properties, such as strongly directional emission, high spatial and temporal coherence and a narrow optical bandwidth.

In other cases, the term laser sources is justified by the fact that the source contains a laser, among other components. This is the case for combinations of lasers and amplifiers (→ master oscillator power amplifier), and also for sources based on nonlinear frequency conversion of laser radiation, e.g. with frequency doublers or optical parametric oscillators.

Safety Aspects

The work with lasers can raise serious safety issues. Some of those are directly related to the laser light, in particular to the high optical intensities achievable, but there are also various other hazards related to laser sources.

See the article on laser safety for details.

Laser Applications

There is an enormously wide range of applications for a great variety of different laser devices. They are largely based on various special properties of laser light, many of which cannot be achieved with any other kind of light sources. Particularly important application areas are laser material processing, optical data transmission and storage and optical metrology. See the article on laser applications for an overview.

Still, many potential laser applications cannot be practically realized so far because lasers are relatively expensive to make – or more precisely because they are so far mostly made with relatively expensive methods. Most lasers are fabricated in relatively small volumes and with a limited degree of automation. Another aspect is that lasers are relatively sensitive in various respects, for example concerning the precise alignment of optical components, mechanical vibrations and dust particles. Therefore, there is ongoing research and development for finding more cost-effective and robust solutions.

For business success, it is often vital not just to develop lasers with high performance and low cost, but also to identify the best suited applications, or develop lasers which are best suited for particular applications. Also, the knowledge of the application details can be very important. For example, in laser material processing it is vital to know the exact requirements in terms of laser wavelength, beam quality, pulse energy, pulse duration etc. for optimum processing results.

More to Learn

Suppliers

The RP Photonics Buyer's Guide contains 242 suppliers for lasers. Among them:

Active Fiber Systems

AFS offers various femtosecond laser platforms based on ytterbium or thulium-doped fiber amplifiers, OPCPA/OPA and XUV extensions covering all wavelength ranges for compact systems up to complex multi-functional beamlines.

Osela

Osela offers a comprehensive range of laser solutions spanning multiple wavelengths, power levels, and beam characteristics. Our diverse portfolio includes UV, red, green, blue, and near-infrared lasers, as well as more unique solutions for complex applications. These lasers incorporate Osela's cutting-edge beam shaping technology, enabling precise control over beam profiles from uniform line, multi-line, structured patterns, True Gaussian, and uniform top-hat distributions. Whether you require a standard off-the-shelf product or a customized solution, our lasers deliver the performance, reliability, and flexibility needed for advanced machine vision, life sciences research, and industrial measurement applications. With options for CW and pulsed operation, variable focus, and modulation capabilities, Osela's lasers provide the versatility to address a wide spectrum of illumination and imaging challenges across multiple industries.

Related products: STREAMLINE LASER | COMPACT LASER | INDUSTRIAL LASER SYSTEM | FIRELINE LASER | TELECENTRIC LASER PROJECTOR | MULTI-LINE PATTERN

Sacher Lasertechnik

Sacher Lasertechnik offers a wide range of diode lasers for scientific and industrial applications, covering a wide range of emission wavelengths and output powers. Apart from DFB and DBR lasers, Fabry–Pérot and tapered amplifier diodes, we offer quantum cascade lasers and terahertz emitters.

RPMC Lasers

RPMC Lasers offers the widest selection of solid-state lasers in North America. From ≈ 1500 standard products to full customization capabilities, we are sure to have what you need: pulsed and CW sources ranging in wavelength from the UV through the LWIR regimes. Pulsed lasers include DPSS lasers, fiber lasers, microlasers/microchip Lasers, ultrafast lasers, and more. Additionally, CW laser modules including single-mode and multimode DPSS laser and laser diode modules are available in both fiber-coupled and free space configurations, as well as gas and fiber lasers, line modules, and many laser diode types, including superluminescent laser diodes, multi-wavelength lasers, and quantum cascade laser diodes. Let RPMC help you find the right laser today!

Thorlabs

Thorlabs manufactures an extensive selection of CW and pulsed laser systems, including picosecond Q-switched lasers with microjoule-level pulses at kHz repetition rates and exceptional beam quality.

LumIR Lasers

LumIR offers mid-IR fiber lasers, based on fluorine glass fibers, with up to 10 W output power and emission wavelength between 2.79 μm and 3.3 μm. They are ideal for medical, material processing and sensing applications.

TOPTICA Photonics

TOPTICA's products provide an ultra-broad laser wavelength coverage: 190 nm – 0.1 THz (corresponding to 3 mm). They enable a big variety of demanding applications in quantum optics, spectroscopy, biophotonics, microscopy, test & measurement, as well as materials inspection. The unique wavelength range is based on three major product categories:

• diode lasers, 190 nm – 4000 nm with frequency-conversion techniques
• ultrafast fiber lasers, 488 nm – 2300 nm (3500 nm customized), 5000 – 15000 nm
• terahertz systems, 0.1 – 6 THz (15 THz customized)

TOPTICA´s Ultra-stable clock laser systems for quantum computing and optical clocks are diode lasers whose linewidth is reduced to less than 1 Hz via frequency stabilization to high-finesse optical ULE cavities.

AeroDIODE

SHIPS TODAY: AeroDIODE offers fiber-coupled laser diodes between 520 nm and 1650 nm as stock items or associated with a CW laser diode driver or pulsed laser diode driver. They are compatible with our high speed nanosecond pulsed drivers or high power CW drivers with air coolingfor the multimode high power laser diode versions. The single mode laser diodes (either Fabry–Pérot laser diode or DFB laser diode) can reach high power in nanosecond pulse regime up to 500 mW. Most turn-key diode & driver solutions are optimized for single-shot to CW performances with pulse durations down to 1 ns. The laser diode precision pulses are generated internally by an on-board pulse generator, or on demand from an external TTL signal. Many multimode versions are available with CW emission up to 300 W in a 200-µm core multimode fiber or up to 250 W in a 135-µm core fiber or 160 W in a 105 µm core fiber.

See also our tutorial on fiber-coupled laser diodes.

AdValue Photonics

AdValue Photonics has developed a number of industrial fiber laser products, operating in different wavelengths regions and pulse duration regimes, or in continuous-wave mode. They are suitable for a range of industrial applications, including laser cutting, drilling and ablation.

See also our overview on fiber laser products!

Megawatt Lasers

MegaWatt Lasers Inc. spezializes on lamp-pumped pulsed lasers for a wide range of applications. Our pump chamber designs provide unsurpassed performance, reliability and leak integrity to meet the demanding needs of your laser system design. Our lasers produce multi-joule nanosecond pulses at eye-safe wavelength, e.g. based on Er:YAG or CTH:YAG rods. We also offer Nd:YAG and alexandrite lasers.

We maintain an inventory of standard pump chambers for immediate delivery, while modular design allows for cost effective custom solutions.

Alpes Lasers

Alpes Lasers offers a wide range of lasers with wavelengths ranging from 4 to 14 μm and powers up to several watts. This includes FP, DFB, THz, frequency comb and external cavity lasers in the mid-IR. Additionally, Alpes offers uniquely fast and widely tuneable lasers with our ET and XT product line.

EKSPLA

EKPLA offers a wide range of femtosecond, picosecond and nanosecond lasers as well as tunable wavelength systems for research and industrial applications.

HÜBNER Photonics

HÜBNER PHOTONICS offers a full range of high performance lasers including single and multi-line Cobolt lasers, tunable C-WAVE lasers, C-FLEX laser combiners. All our lasers are manufactured in a clean room environment, by skilled staff and with the highest of quality.

NKT Photonics

NKT Photonics is at the forefront of optical fiber and laser technology. Expect exceptional performance when you want to push forward and move the definition of what’s possible. We offer a wide range of lasers spanning from pulsed diode lasers and single-frequency fiber lasers over ultrafast fiber lasers and femtosecond lasers to supercontinuum white light lasers. Whatever your laser needs, we have a system for you!

Radiantis

Radiantis manufacturers broadly tunable laser systems based on Optical Parametric Oscillators (OPOs). Femtosecond, picosecond and continuous-wave (CW) lasers are available that cover the visible and IR spectral regimes. The laser systems include both a pump laser and the OPO in the same enclosure.

Customised devices for specific wavelengths or pulse duration can be developed.

Edmund Optics

Edmund Optics offers a wide range of laser sources, including machine vision lasers, life science lasers, metrology lasers, gas lasers, industrial and point lasers, and material processing lasers.

Stuttgart Instruments

The Stuttgart Instruments Alpha is an ultrafast and fully wavelength-tunable frequency conversion system in an ultra-compact and completely passively stable system based on revolutionary parametric oscillator design which guarantees outstanding stability, reproducibility and shot-noise limited performance.

The revolutionary design of Stuttgart Instruments Alpha, characterized by outstanding low noise and passive long-term stability, is based on the fiber-feedback optical parametric oscillator (FFOPO) technology and results in outstanding performance and high flexibility at the same time.

The Alpha covers a gap-free rapid tunable spectral range from 700 nm to 20 µm wavelengths, while maintaining high output power up to the Watt-level with femto- or picosecond pulses at several MHz pulse repetition rates. It provides multiple simultaneously tunable outputs with a selectable bandwidth from a few to 100 cm-1. Shot-noise limited performance above 300 kHz, passive spectral stability (< 0.02% rms) and wavelength-independent stable beam pointing (< 30 µrad) enable excellent sensitivity. In addition, each Alpha is equipped with a user-friendly ethernet and Wi-Fi interface and a matching graphical user interface (GUI) as well as easy to access API interfaces for e.g. LabView, Python, C++.

Typically, the Alpha is pumped by an ultra-low-noise Primus pump laser, which provides more than 8 W average output power at 1040 nm wavelength and 450 fs pulse duration at 42 MHz repetition rate. In addition, the Alpha can be operated with other pump lasers around 1 µm wavelength and enough power.

Due to our modular platform, the Alpha can be adapted and optimized for various applications and is particularly suited for spectroscopic applications requiring a robust and reliable tunable radiation with low noise.

Shalom EO

Hangzhou Shalom EO offers two kinds of OEM laser modules: eye-safe 1535-nm laser modules and lasers integrated with MgO:PPLN waveguides. Shalom EO’s OEM laser modules provide precise, reliable, and efficient laser sources that can be seamlessly integrated into other systems, accommodating specific application requirements.

Shalom EO’s 1535-nm eye-safe OEM pulsed lasers use Er:Yb:glass as the laser gain media and Co:MgAl₂O₄ (Co:spinel) as the passive Q-switch, generating laser pulses of nanoseconds of pulse duration. With a wavelength of 1535 nm, the lasers are designed to minimize the risk of retinal or corneal damage. Modules with a low repetition rate of 10 Hz and a high repetition rate of up to 1 kHz are available. With rugged design and superior temperature resistance, Shalom EO’s 1535-nm laser modules are excellent for applications such as laser range finders, Lidar, and medical treatments.

Shalom EO’s MgO:PPLN laser module utilizes an MgO:PLLN waveguide as the nonlinear frequency conversion component, which is assembled with the pumping LD, Nd:YVO₄ or Nd:YAG laser crystals, and optics. Shalom EO offers a range of standard output wavelengths, including 473 nm, 532 nm, 545 nm, 561 nm, and 671 nm. In addition, we can accommodate custom output wavelengths upon request. Our MgO:PPLN waveguides are designed with compact dimensions, these laser modules feature high output power, strong power stability, and exceptional conversion efficiencies.

Vexlum

VEXLUM offers watt-level single-frequency lasers based on VECSEL technology with broad wavelength coverage. Our product lines include:

• VALO, offering flexibility for research applications such as quantum technology and spectroscopy.
• VXL®, a new compact and modular industrial single-frequency product line, designed for system integration in semiconductor, metrology, and medical applications.

Wavelengths range from 350 nm to 2150 nm, and power levels up to 10 W.

Optogama

Optogama offers various types of lasers: eye-safe 1,54 μm diode-pumped passively Q-switched and CW erbium glass lasers as well as passively Q-switched Nd:YAG lasers.

Eye-safe 1,54 μm wavelength nanosecond lasers of the “KAUKAS“ (1, 2, 3) series have a unique compact design and are available in OEM models for dedicated applications. These lasers deliver up to 3 mJ energy per pulse with pulse duration <10–15 ns, TEM₀₀ beam profile and repetition rate of up to 5 Hz.

„KAUKAS HR“ laser models have adjustable repetition rate feature and deliver more than 30 µJ energy per pulse with a repetition rate of up to 1 kHz available on request.

“KAUKAS CW” diode-pumped, solid-state laser models deliver up to 400 mW of continuous-wave power at 6 wavelength in the 1,5–1.6 μm spectral range.

Nd:YAG passively Q-switched lasers of the "WAVEGUARD" series with sub-nanosecond pulse widths and a peak power of several tens of kilowatts are very compact. Additional harmonics modules for 532 nm, 355 nm, or 266 nm wavelengths are available on request for all models.

QPC Lasers

QPC Lasers manufactures fiber-coupled diode laser modules with the highest powers and brightness in the industry at wavelengths ranging from 780 to 2000 nm.

Products range from sub-watt single-mode PM fiber coupled diodes for LIDAR and communications to multi-mode fiber-coupled modules with outputs in the hundreds of watts for medical, materials processing and pumping applications. Optional features include Brightlock monolithically spectrally stabilized diodes for unmatched linewidth and spectral control.

Class 5 Photonics

Class 5 Photonics delivers ultrafast, high-power laser technology at outstanding performance to advance demanding applications from bio-imaging to ultrafast material science and attosecond science. Our robust optical parametric chirped pulse amplifiers (OPCPA) provide high-power, tunable femtosecond pulses and user-friendly operation.

Bright Solutions

Bright Solutions offers various types of lasers:

• fiber-coupled diode laser modules
• various types of nanosecond Q-switched lasers and MOPAs, e.g. for LIDAR, laser machining or lithography
• narrowband picosecond lasers, e.g. for OPO pumping, Raman or fluorescence spectroscopy and multimodal imaging

FYLA LASER

At FYLA we develop ultrafast fiber lasers with pulse durations in the range of picoseconds and femtoseconds. Our lasers are used in a lot of applications, from microscopy (single-molecule fluorescence, OCT, FRET, TIRF, etc.) up to optical characterization, providing a greater level of robustness, higher lifetimes, and a cost-effective solution.

Lumibird

Lumibird manufactures a wide range of lasers thanks to its expertise in three key technologies: pulsed solid-state lasers (nanosecond range), CW and pulsed fiber lasers and fiber amplifiers, and laser diodes. Various application areas are addressed, in industry (manufacturing, lidar sensors), science (laboratories and universities), medical (ophthalmology) and defense.

Lumics

Lumics is a vertically integrated manufacturer producing high-quality laser diodes, with in-house chip production and integration into various single emitter packages and designs. Lumics offerings include pigtailed single-mode and multi-mode packages, covering a broad wavelength and power range, designed for different fiber core sizes. Lumics' high-power multi-mode diode laser modules span wavelengths from 670 nm to 1940 nm, supporting multi-wavelength configurations, ideal for applications in medical, life science, analytics, material processing, pumping, seeding, and printing. All diodes feature patented facet technology, ensuring exceptional lifetimes and reliability.

GWU-Lasertechnik

GWU-Lasertechnik has more than 30 years of experience in lasers and nonlinear optics. We are the pioneer of commercial BBO OPO technology. Our widely tunable laser sources cover the spectral range from the deep-UV at <190 nm to the IR at >2700 nm. We offer pulsed solutions for nano-, pico- and femtosecond pulses with best performance and highest reliability.

CNI Laser

CNI offers a wide range of lasers, including

• laser diode modules, e.g. narrow-linewidth DFB lasers, picosecond lasers, alignment lasers and others
• diode-pumped solid-state lasers with high stability, low noise, high output power or pulse energy, Q-switched and mode-locked picosecond versions, etc.
• fiber lasers with SM or MM fiber output, pulse width <200 ps, tunable versions with 1–250 ns pulse width, modulation rates up to 1 MHz

and various others. We specialize in designing and manufacturing custom-made and OEM lasers to suit our clients' particular needs. In fact, 75% of the lasers manufactured involve some type of custom work.

Bibliography

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Questions and Comments from Users