Passive Q-Switch Lasers

Image Pulsed DPSS Lasers Saturable Absorber Passive Q-Switch Example DiagramPassive q-switches use a saturable absorber, which can be a crystal (typically Cr:YAG), a passive semiconductor, or a special dye. Passive q-switches take advantage of a process known as saturable absorption.  Saturable absorption derives from the fact that there is a limit to the amount of light that a material can physically absorb at a given wavelength before the energy level becomes saturated and the material becomes temporarily transparent.  As a result, if a saturable absorbing material is placed inside of the laser cavity, it will absorb all of the spontaneously emitted photons until it reaches saturation where it will then allow the photons to pass through and initiate stimulated emission.  In a saturable absorber, the time it takes for for excitation to resolve after after stimulation by an energy source is referred to as recovery time. Ideally, the recovery time is some period longer than that of the pulse duration. This condition helps avoid undesired energy loss. However, if recovery time is too long, premature lasing can occur when the laser’s gain recovers and the saturable absorber is still ‘open.’ A good rule of thumb is to have a recovery time that is longer than the pulse duration, but shorter than the upper-state lifetime of the gain medium to avoid unwanted lasing and pulse issues.

You can find Active Q-Switch Lasers Here.

Our Products

RPMC offers a selection of passively Q-switched lasers, including Pulsed DPSS Lasers, Ultrafast Lasers, Microchip Lasers (Microlasers), and MIL-Spec. Lasers. Wavelength options include the UV, Blue, Green, NIR, and SWIR spectral regions, and pulse width options available from 40ns down to 7 ps.

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In conclusion, if you have any questions or would like some assistance please contact us here. Furthermore, you can email us at [email protected] to talk to a knowledgeable Product Manager. Alternatively, use the filters on this page, or check out our ‘How to Select a Pulsed Laser‘ version of this page to assist in narrowing down the selection. Finally, head to our Knowledge Center with our Lasers 101 page and Blogs and Whitepapers pages for further, in-depth reading.

Suggested Reading

The Advantages and Disadvantages of Passive vs Active Q-Switching

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Nps Series


The NPS series of ultrafast lasers is the ultimate solution for OEM integrators and researchers working with nonlinear optics applications like OPO pumping and narrowband Raman spectroscopy. The NPS series boasts remarkable features such as up to 10W average output power, <7ps pulse width, and a 40MHz repetition rate. The transform-limited operation, with a spectral width of <0.3nm, and accurate central wavelengths make these lasers a suitable candidate for highly efficient amplification by Nd-doped DPSS amplifiers.

One Series

One-1030-100: 1030nm Miniature Q-Switched Laser

The One Series is a versatile, passively q-switched laser series designed specifically for OEM integrators and application specialists working with industrial and portable applications like materials processing and airborne LIDAR. With its compact size and ability to operate at a fundamental wavelength of 1030nm, this series offers exceptional performance for a range of applications. The One Series can be configured in a fixed operational rep rate configuration, or an externally triggerable configuration. Available in both high energy configurations (up to 100uJ) and high average power configurations (up to 3W), the One series is a reliable choice for any application. 

Microchip Series

Bright Microlaser Microchip SB1 Laser

The Microchip series is a line of ultra-compact, passively q-switched, single longitudinal mode (SLM), narrow linewidth, DPSS lasers that offer exceptional performance in a compact form factor. The lasers feature pulse durations ranging from 400 ps to 2 ns, energy levels up to 80 µJ, and repetition rates up to 100 kHz. Available in wavelengths from the UV to the NIR, this series is designed for OEM integrators and researchers working with LIDAR, 3D scanning, LIBS, night vision, and more. The lasers offer both nanosecond and picosecond options and are interchangeable with the same form factor and electrical and software interfaces across wavelengths, making them a flexible and versatile solution.