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Q-Switches (AOQS)

An acousto-optic Q-switch (AOQS) works within a laser cavity to generate high intensity, pulsed light by actively controlling the Q-factor (loss) of the cavity. Our acousto-optic Q-switches are rugged, reliable, and long-lasting, backed by millions of hours of service in the field.

We offer low insertion loss, highly efficient acousto-optic Q-switches capable of handling very high peak power, and will draw on our 35 years of experience to match the cavity length, repetition rate, wavelength, beam diameter, polarization state and output power of a laser to the best acousto-optic Q-switch solution.

When placed inside a laser cavity, an acousto-optic Q-switch (AOQS) can be used to control the amount of light circulating within the resonator via the acousto-optic effect. When turned on, an AOQS diffracts light out of the optical beam path within the cavity, thus increasing losses and reducing the Q-factor. While loss in the cavity is high and pumping continues, lasing cannot occur, but a population inversion can build up within the gain medium. Once the gain is saturated, the RF power to the acousto-optic Q-switch is turned off, reducing loss within the cavity very quickly. This increases the Q-factor and allows rapid amplification to create a very high intensity, short pulse.

A high quality acousto-optic Q-switch has several important characteristics:

  • Very low loss in the “off” state to maximize output intensity
  • Ability to withstand very high peak laser power
  • Excellent transducer reliability to allow long-term use without maintenance

We consider many factors in identifying or creating the right acousto-optic Q-switch and driver for an application:

  • Cavity length
  • Beam diameter
  • Wavelength
  • Polarization state
  • Repetition rate
  • Output power
  • Location of the Q-switch within the cavity

To avoid sacrificing diffraction efficiency, there is a tradeoff between the RF power applied and durability. More rugged or durable acousto-optic Q-switch materials generally require more RF drive power, and may need water or conduction cooling.

We have off-the-shelf solutions for polarized or unpolarized lasers at near infrared wavelengths. We can accommodate large lamp pumped multimode laser beam diameters (up to 8 mm) as well as small compact diode pumped beam diameters (< 1 mm) with both water and conduction cooling. Specialized designs meet unique needs such as ultra-high single pass loss (up to 96%), high switching speeds, and premium pulse-to-pulse stability.

We also offer a full line of RF drivers designed specifically for Q-switching, with rapid fall times, tight synchronization, operation in either fixed or variable mode, and advanced capabilities like first pulse suppression or multichannel operation to drive multiple Q-switches within the same cavity.

Whether you are designing a laser for materials processing applications (engraving, cutting or drilling), or creating a full system for medical surgery, lithography or rapid prototyping, we can find the Q-switch and RF driver to balance your performance, cost, and reliability needs.  

Applications of acousto-optic Q-Switches

Laser marking, lithography, material processing, medical surgery, micromachining

ProductWavelengthActive ApertureOperating FrequencyOptical MaterialType