Mark Hewko from the Institute of Biodiagnostics National Research Council Canada recently purchased a Diffractive Variable Attenuator (DVA) for use with a Spectra-physics Tsunami fs laser (780 to 850nm operation with 800mW of output, 100fs pulse at 80MHz).
He wrote to us recently:
To date the unit functions quite well by maintaining beam pointing direction
while varying output power.
National Research Council
Institute for Biodiagnostics
435 Ellice Ave
Diffractive attenuators control the power of laser radiation using diffraction gratings. Since phase diffraction gratings do not absorb light they can be used for high-power laser radiation (CW, pulsed). Variation of grating parameters along the substrate results in variable transmission at a given wavelength.
Diffractive Variable Attenuators are based on binary optics technology. Attenuator manufacturing starts from computer design of two-dimensional diffractive gratings using proprietary Diffraction Optics Design Software DOD-Master(TM). Master Grating mask is created using high-resolution laser photo plotters. Final manufacturing process is accomplished using lithographic methods including plasma etching.
Diffractive attenuators are designed for wavelength from deep UV to IR. Damage threshold for these high power attenuators is more than 250W/cm2 in CW and 1000 mJ/cm2 in 10ns pulses.
DVA works at design wavelength and at 1/3 of that wavelength. That is why we offer standard models for 1064nm (355nm), 800nm (266nm) and 532nm. Outside of design wavelength (for more than +/-15%) the diffraction efficiency of the gratings and thus attenuation ratio will get lower.
Del Mar Photonics - Diffractive Variable Attenuator Brochure - buy online
Del Mar Photonics diffractive optics elements including Diffractive Variable Attenuators for high power lasers are manufactured using Circular laser writing system CLWS-300/C
Laser pattern generator CLWS-300/C is used for manufacturing of binary amplitude masks of computer-synthesized holograms with arbitrary topology, multi-level axial-symmetric diffractive optical elements, precision circular scales for angular encoders and limbs. Laser writing system CLWS-300/С is intended for direct laser writing of diffractive structures on chromium and photoresist films. Writing process is carried out in polar coordinates system.
Additional information about Circular Laser Writing Systems CLWS-300/C and CLWS-200
If you are interested in acquiring of CLWS please e-mail us at firstname.lastname@example.org
Del Mar Photonics