Laser Light

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

Definition: light generated with a laser device

Alternative term: laser radiation

More general term: light

Categories: article belongs to category general optics general optics, article belongs to category laser devices and laser physics laser devices and laser physics

DOI: 10.61835/yet Cite the article: BibTex plain text HTML Link to this page LinkedIn

Laser light (laser radiation) is light generated with a laser device. Such light has some very special properties, which very much distinguish it from light with other origins:

Laser light is usually delivered in the form of a laser beam, i.e. it propagates dominantly in a well-defined direction with moderate beam divergence. Such a laser beam has a high (sometimes extremely high) degree of spatial coherence. This means that the electric fields at different locations across a beam profile oscillate with a rigid phase relationship. Exactly this coherence is the reason why a laser beam can propagate over long distances without spreading very much in the transverse directions, and why it can be focused to very small spots (high focusability of laser beams).
In many but not all cases, laser light also has a high degree of temporal coherence, which is equivalent to a long coherence length. This means that a rigid phase relationship is also maintained over relatively long time intervals, corresponding to large propagation distances (often many kilometers) or to huge numbers of oscillation cycles.
The large temporal coherence, quantified with a large coherence time or coherence length, is associated with a narrow spectral bandwidth (or linewidth). (We exclude here the sophisticated case of trains of ultrashort pulses, which can have a large optical bandwidth but nevertheless a high degree of coherence; see the article on coherence for details.) For a visible laser beam, this means that it has a certain pure color, e.g. red, green or blue, but not white or magenta. Some lasers allow a degree of wavelength tuning (e.g. dye lasers). The large coherence length introduces a tendency for the phenomenon of laser speckle, i.e. a characteristic granular pattern which can be observed e.g. when the laser beam hits a metallic surface.
In many cases, laser light is linearly polarized. This means that the electric field oscillates in a particular spatial direction (→ polarization of light). Cases with other well-defined polarization states, e.g. circular polarization, also occur, and can be relevant for certain applications (for example, for laser drilling).

Depending on the case, laser light can have other remarkable properties:

Laser light may be visible, but many lasers actually emit in other spectral regions: most frequently, in the near-infrared region, which human eyes cannot perceive.
Laser light is not always continuous, but may be delivered in the form of short or even ultrashort pulses. As a consequence, the peak power can be extremely high – for some amplified laser systems, well above 1 TW (10¹² W) – if the pulse duration is far below the temporal distance of subsequent pulses, so that a large pulse energy is possible.
The noise properties of lasers can also be very interesting (→ laser noise). For example, the oscillation frequency of a laser can be stabilized to stay within an extremely narrow range. This is relevant for optical clocks.

For comparison, light from an incandescent lamp is partly visible and mostly infrared, has a very high spectral bandwidth, cannot be strongly focused (because of low spatial coherence), and cannot be generated in the form of short pulses.

Laser light can cause significant hazards, particularly for the eye, but also for the skin, apart from fire hazards and others. Lasers pulses are often particularly dangerous because they can have enormously high optical intensities, and invisible laser beams add specific risks. See the article on laser safety for details.

More to Learn

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Suppliers

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

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.

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.

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!

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.

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.

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.

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.

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.

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!

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.

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.

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.

Frankfurt Laser Company

Frankfurt Laser Company offers the widest wavelength range for laser diodes on the world market from 370 nm to 12 µm, single mode & multimode, broad area, DFB and DBR, fiber Bragg grating stabilized, quantum cascade, VCSELs, superluminescent diodes and mid-IR light emitting diodes. We offer wavelength selection and custom packaging; please contact us to discuss your requirements.

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.

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.

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.

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.

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.

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.

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

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!

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.

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.

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.

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 – 3500 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)

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