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Picosecond Lasers

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

Definition: lasers emitting pulses with picosecond durations

More general terms: pulsed lasers, mode-locked lasers

Categories: article belongs to category laser devices and laser physics laser devices and laser physics, article belongs to category light pulses light pulses

DOI: 10.61835/6kj Cite the article: BibTex plain text HTML Link to this page LinkedIn

A picosecond laser is a laser which emits optical pulses with a duration between 1 ps and (usually) some tens of picoseconds. It thus also belongs to the category of ultrafast lasers or ultrashort pulse lasers.

Sometimes, other laser-based sources for picosecond pulses – for example synchronously pumped OPOs – are also called picosecond lasers, even if they are strictly speaking no lasers.

A variety of laser types can generate picosecond pulses, with other performance parameters varying in wide ranges:

The most common sources are actively or passively mode-locked solid-state bulk lasers. These can provide very clean (transform-limited and low-noise) ultrashort pulses with pulse repetition rates varying from a few megahertz to more than 100 GHz. For example, a passively mode-locked Nd:YAG or vanadate laser can easily generate e.g. 10-ps pulses with several watts of output power, and thin-disk lasers can generate many tens of watts in shorter pulses.
Mode-locked fiber lasers can also cover a wide range of repetition rates from a few megahertz up to more than 100 GHz (with harmonic mode locking). Particularly with MOPA or MOFA systems, very high average output powers are possible. The pulse quality from such sources varies; for example, the pulses may or may not be close to bandwidth-limited.
Lower repetition rates are possible with an additional pulse picker and also allow for amplification to higher pulse energies e.g. with a regenerative amplifier, possibly using chirped-pulse amplification. Cavity dumping of a mode-locked laser is another option.
Laser diodes can be mode-locked for picosecond pulse generation (→ mode-locked diode lasers). This leads to compact sources with typical pulse repetition rates between 1 GHz and hundreds of gigahertz. However, the pulse energy is severely limited, and the pulse quality is not always high.
Laser diodes can also be gain-switched with carefully designed electronics to achieve pulse durations of well below 1 ns, sometimes even below 100 ps. This leads to very compact and potentially cheap sources, and another advantage is that the pulse repetition rate can easily be varied in a very wide range simply via the driver electronics. See the article on picosecond diode lasers.
Although Q-switched lasers typically generate nanosecond pulses, Q-switched microchip lasers can reach pulse durations far below 100 ps.
More exotic sources of picosecond pulses are free electron lasers, which can provide high pulse energies even in extreme wavelength regions.

Applications of Picosecond Lasers

Picosecond lasers are used in a wide range of laser applications. Some of these lasers are industrial lasers, while others are scientific lasers. Some typical applications are discussed in the following.

Laser Material Processing

In laser material processing, e.g. laser drilling or cutting, it is often advantageous to use very short light pulses having correspondingly high peak powers for a given pulse energy. Nanosecond pulse durations (from nanosecond lasers) are often too long because a substantial spread of deposited energy can occur by thermal conduction during the pulse duration. This is quite different for pulse durations of e.g. 10 ps or less, where there is minimum heat diffusion during the pulse duration. As a result, substantially finer structures can be processed with high quality (laser micromachining). Note, however, that high quality results usually require a careful optimization of many process details.

Compared with femtosecond lasers, picosecond laser sources are often more economical: a higher average output power is available at a lower price. In applications such as laser micromachining, one sometimes achieves better quality results with femtosecond pulses, but picosecond pulses are often sufficient when the process is sufficiently optimized overall. In such cases, picosecond lasers are often preferred.

Medical Applications

There are some medical applications where picosecond pulses have advantages. A common application is the removal of tattoos, and similarly one may reduce pigments of natural origins. There are also surgical procedures where precise material ablation can be achieved with picosecond pulses.

Laser Microscopy

Some laser microscopes are operated with picosecond pulses, although femtosecond pulses have substantial advantages in some cases.

OPO Pumping

Many synchronously pumped optical parametric oscillators are pumped with picosecond lasers. Sometimes, the whole setup is still called a picosecond laser, even though it also contains an OPO.

Measurements

Picosecond laser pulses are useful for a very wide range of measurements. For example, distance measurements with LIDAR, e.g. based on time-of-flight measurements, can be performed. Picosecond pulses are also often used in pump–probe measurements on timescales of multiple picoseconds to nanoseconds.

Telecommunications

In the area of optical fiber communications, picosecond lasers can be used in different ways. For example, picosecond lasers may be used for generating soliton pulses in optical fibers, which propagate without dispersive broadening. For such purposes, compact and cheap lasers with gigahertz repetition rates, often with emission in the 1.5-μm telecom bands, are required.

More to Learn

mode-locked lasers mode locking ultrafast lasers femtosecond lasers ultrashort pulses

Suppliers

The RP Photonics Buyer's Guide contains 90 suppliers for picosecond lasers. Among them:

Radiantis

Radiantis Zenith is a broadly tunable picosecond laser system, tunable across 1450 – 4000 nm. This system incorporates a pump laser and an Optical Parametric Oscillator (OPO) which provides fully automated tuning and high power on a integrated and robust platform.

Bright Solutions

Bright Solutions has the NPS narrowband picosecond lasers:

1064, 532 or 355 nm
7-ps pulses at 40 MHz
spectral width < 0.3 nm
10 mW average output power; custom Nps-1064-k2 with amplifier for 2 W output power

The NPS lasers are suitable for applications like OPO pumping, Raman or fluorescence spectroscopy and multimodal imaging.

CNI Laser

CNI offer mode-locked picosecond lasers with superior beam quality and high reliability. The pulse duration can be less than 20 ps. Available wavelengths are 266 nm, 355 nm, 532 nm, 1064 nm, 1319 nm and others.

RPMC Lasers

Serving North America, RPMC Lasers offers one of the widest wavelength selections of picosecond lasers available, ranging from the UV through the SWIR regimes. Our offerings include pulsed DPSS lasers, fiber lasers, and microchip lasers with pulse energy up to a few mJ and pulse repetition rates up to 80 MHz. With many standard configurations, various options and add-ons, and full customization capabilities, we're sure to have the right fit. Let RPMC help you find the right laser today!

FYLA LASER

Iceblink is a supercontinuum fiber laser covering the 450–2300 nm spectral range with 3 W of average power and superior stability (<0.5% std. dev.). It is a very versatile white light source with a world of applications in the scientific and industrial sectors, including absorption/transmission measurements for material characterization, VIS, NIR, IR spectroscopy, single molecule spectroscopy, and fluorescence excitation. The spatial coherence and broad spectrum of Iceblink make it a great alternative to classic lamps, single-line lasers, LEDs, and ASE sources.

ALPHALAS

The ALPHALAS product line of PICOPOWER series ultrafast lasers implements advanced methods for generating picosecond pulses, including active, passive or combined mode-locking. ALPHALAS is the only manufacturer that uses the patented and most advanced “Nonlinear Mirror” or “Stankov Mirror” mode-locking method based on second harmonic generation with practically unlimited power scaling.

The product line includes cavity-dumped mode-locked lasers, regeneratively amplified picosecond pulses with unsurpassed low jitter < 3.5 ps for pulses “on demand” and MW peak power. Optional harmonic wavelengths are also available.

The PICOPOWER-LD series of the proprietary picosecond diode lasers covers the range 375 nm to 2300 nm with picosecond pulses as short as 12 ps and high peak power more than 2 W for specific wavelengths. Numerous applications cover optical parametric generator pumping, nonlinear optics, spectroscopy time-resolved spectroscopy, remote sensing and material processing.

MPB Communications

Based on an all-fiber design, MPBC’s all-fiber mode-locked picosecond laser (AFML) is highly reliable and maintenance-free. It delivers pulses through polarization-maintaining fiber, with a very broad spectral bandwidth exceeding 15 nm at FWHM. Our patented Figure-8 technology ensures reliable and consistent mode-locking, ideal for long-term stable operation in challenging environments.

Additionally, we have picosecond mode-locked fiber lasers which operate at 515 nm, 532 nm, and anywhere between 920-1080 nm. These lasers are ideal if a fast repetition rate (≤100 MHz) and a nearly transform-limited spectral bandwidth is required. Average output power varies from 2 to 3000 mW, depending on the configuration.

These lasers are designed to address a range of market applications including semiconductor inspection, micro-machining, metrology, bio-medical imaging, and can be used as a seed source for optical amplifiers, and second harmonic generation.

NKT Photonics

Our PILAS range of gain-switched pulsed diode lasers are designed for industrial as well as scientific applications. Get a flexible system to fit any application. Choose from more than 10 different wavelengths in the range from 375-1550 nm, repetition rates from single-shot to 40 MHz pulse trains, internal or external triggers. With PILAS you get alignment and maintenance-free 24/7 operation.

APE

The picosecond laser source picoEmerald emits ultra-short pulses with a duration of 2 picoseconds (other durations possible). The wavelength tuning of the ps laser is fully automated across a tuning range of 700 to 990 nm (signal) and 1080 nm to 1950 nm (idler). The fundamental beam at 1032 nm is also available. A wavelength scan / sweep function for fast spectra acquisition over certain specific wavelengths is included.

The key-facts of the picoEmerald are:

wavelength 1 IR beam 1032 nm
wavelength 2 tunable 700 – 990 nm
wavelength 3 tunable 1080 – 1950 nm
80 MHz pulse repetition rate
temporal and spatial overlap of the output wavelengths
integrated time delay between the wavelengths
common output port for all beams
fully automated wavelength tuning
EOM optionally integrated

Stuttgart Instruments

The Stuttgart Instruments (SI) Piano Laser System is a narrowband very precise infrared light source for a wide range of analytical applications in spectroscopy and microscopy to study the chemical and structural composition and behavior of materials on the nanoscale. In this context, the SI Piano is characterized by its outstanding precision, spectral flexibility and unbeatable reproducibility; packaged in a compact and comparably low-cost design. This enables new research approaches for the materials of the future, and also achieves transmission from science to industry

Picophotonics

Compact microchip lasers with 50–300 ps pulse duration, tunable repetition rates from 10 kHz to 200 kHz with µJ pulse energies in turn-key platform with integrated electronics and OEM version at both 532 nm and 1064 nm.

AdValue Photonics

AdValue Photonics offers the EVERESTpico 1 μm picosecond fiber laser (AP-1030P), Different models can deliver 50-ps pulses with 15 W, 30 W, 60 W or 100 W average power in a collimated free-space beam with excellent beam quality. Pulse repetition rates can go up to 1 MHz.

There is also the EVERESTpico green picosecond laser for applications like laser cutting, drilling and scribing on various materials. Different models can deliver 50-ps pulses with up to 30 W average power and excellent beam quality.

TOPTICA Photonics

TOPTICA offers next generation ultrafast picosecond and femtosecond fiber lasers for science and industry. The key for successful integration of ultrafast technology are robust, cost-effective systems with simple push-button operation. TOPTICA offers several products fulfilling these requirements: ultrafast fiber lasers based on erbium (Er) and ytterbium (Yb).

Teem Photonics

Teem Photonics offers a wide range of lasers with pulse durations as short as 100 ps. For example, the 266 nm PNU-M01210-1x0 laser, belongs to the Powerchip laser series, which also covers wavelengths of 1064 nm, 532 nm, 355 nm and 213 nm with pulse durations below 500 ps. Peak powers of tens of kilowatts (or even 160 kW at 1064 nm) are generated. Compared with mode-locked picosecond lasers, the pulse repetition rates are limited to about 100 kHz), while the pulse energies are far higher – tens of microjoules.

EKSPLA

Due to their excellent stability and high output parameters, EKSPLA scientific picosecond lasers established their name as “gold standard” among scientific picosecond lasers. The innovative design of the new generation of picosecond mode-locked lasers features diode-pumping‑only technology, thus reducing maintenance costs and improving output parameters. Second, third, fourth and fifth (on some versions) harmonic options combined with various accessories, advanced electronics (for streak camera synchronization, phase-locked loop, synchronization of fs laser) and customization possibilities make these lasers well suited for many scientific applications, including optical parametric generator pumping, time-resolved spectroscopy, nonlinear spectroscopy, remote sensing, metrology and others.

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