UV/VIS Wavelength Generation
SHG
Second Harmonic Generation
The Sirah Frequency Conversion Unit (FCU) is designed to frequency double a dye laser beam. Typically, the dye laser is operated in the visible spectral range. This frequency is doubled by a BBO crystal followed by a compensator. The crystal’s angle is tuned to maintain phase matching inside of the crystal. This can be done by Look-Up-Table or autotracker. Both tracking methods are included. The autotracker is using a pyroelectric detector, which is only sensitive to pulsed light. An arrangement of 2 or 4 Pellin-Broca prisms (WS-2 or WS-Auto, please order separately) separates the UV from the fundamental beam. The FCU may be integrated into the laser housing (not possible for the Cobra model) or attached
externally to the laser (add FC-EXH housing). All crystals, compensators and Pellin-Broca prisms are fully adjustable, making the unit easy to use.
Tuning curves for the frequency doubled dye laser. At a given wavelength full energy is only obtained if resonator configuration is suited.
External Housing (FC-EXH)
All Dimensions in mm. Specifications are subject to change without notice.
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THU 205
Third Harmonic Generation
The THU 205 (third harmonic unit) is designed to generate laser radiation in the UV wavelength range, from 197 nm to 260 nm, by third harmonic generation (THG). It is operated together with a Cobra-Stretch or PrecisionScan dye laser, ideally pumped by an injection seeded frequency doubled Nd:YAG laser. The dye laser is operated in the red spectral range from 591 nm to 780 nm. Its output beam is first frequency doubled by a temperature stabalized BBO crystal. A set of 4 dichroic mirrors separates the generated UV beam from the two incoming. Due to the short wavelength, different dichroic sets are necessary to cover the wavelength range of the THU 205. Alternativly a wavelength separation with four Pellin-Broca prisms made of very high quality CaF2 can be used. The unit is mounted vertically behind the THU 205 (+ 171 mm in length). It can be mounted also horizontally behind the doubling unit for separation of the second harmonic generation (SHG).
Tuning curves for 500 mJ @ 532 nm pump laser energy.
All Dimensions in mm. Specifications are subject to change without notice.
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MAD
Mixing After Doubling
The Sirah MAD-195 (mixing after doubling) is designed to generate laser radiation in the UV wavelength range from 190 nm to 202 nm. It is operated together with a Cobra-Stretch or PrecisionScan dye laser, pumped by an injection seeded Nd:YAG laser.
The dye laser is operated in the blue spectral range, from 462 nm to 490 nm. Its output beam is first frequency doubled by a BBO crystal. Then, the resulting UV beam is sum frequency mixed with the residual fundamental Nd:YAG radiation. A set of 4 dichoic mirrors separates the generated UV beam from the two incoming beams. Additionally, the MAD-195 unit may easily upgraded to a third harmonic generation unit (THU-205), giving access to wavelength from 197 nm to 212 nm..
All Dimensions in mm. Specifications are subject to change without notice.
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SFM 355
Sum Frequency Mixing with 355 nm
The SFM-355 mixing unit is designed to generate laser radiation in the UV wavelength range, from 214.6 nm to 241 nm. It is operated together with a Cobra-Stretch or PrecisionScan dye laser, ideally pumped by an injection seeded frequency doubled Nd:YAG laser. Generation of wavelengths around 220 nm by mixing is an alternative to the use of frequency doubled (SHG) blue dyes pumped by the frequency tripled YAG. The advantage of this approach is the superior lifetime of the used dyes and the smaller spectral bandwidth of the generated UV radiation, in case a seeded Nd:YAG laser is used. Although the SFM set-up is more complex, the versatile design permits standard SHG if required. The dye laser is operated in the red spectral range, from 542 nm to 751 nm. Its output beam is sum frequency mixed with the frequency tripled Nd:YAG radiation. Four Pellin-Broca prisms separate the generated UV beam from the dye and Nd:YAG beams.
Tuning curves with different dyes, when using approximately 600 mJ @ 532 nm for pumping and 300 mJ @ 355 nm for mixing.
All Dimensions in mm. Specifications are subject to change without notice.
Literature & Downloads
SFM 1064
Sum Frequency Mixing with 1064 nm
The SFM-1064 mixing unit is designed to generate laser radiation in the UV wavelength range from 360 nm to 440 nm. It is operated together with a Cobra-Stretch or PrecisionScan dye laser, ideally pumped by an injection
seeded frequency doubled Nd:YAG laser.
Generation of wavelengths around 400 nm by mixing is an alternative to the use of blue dyes pumped by the frequency tripled YAG. The advantage of this approach is the superior lifetime of the used dyes and the smaller spectral bandwidth of the generated UV radiation, in case a seeded Nd:YAG laser is used. Although the SFM set-up is more complex, the versatile design permits standard SHG if required.
The dye laser is operated in the red spectral range, from 542 nm to 780 nm. Its output beam is sum frequency mixed with the fundamental Nd:YAG radiation at 1064 nm. Four Pellin-Broca prisms separate the generated UV beam from the dye and Nd:YAG beams.
Tuning curves with different dyes, when using approximately 850 mJ @ 532 nm for pumping.
All Dimensions in mm. Specifications are subject to change without notice.