- Wide Spectral Range 250 nm to 1100 nm
- High Extinction Ratio
- Negligible Piezoelectric Response
- High Damage Threshold
- High Average Power Capability
- Single & Double Crystal Configurations
BBO (Beta Barium Borate) is noted for its excellent optical quality and low strain birefringence. This
results in high extinction ratios and low wavefront distortion. Low absorption provides excellent
transmission efficiency in the UV and near IR. Qswitches fabricated from BBO can be operated at
high repetition rates and high average power.
Operation of BBO modulators and Q-switches from single shot to repetition rates of more than 50 kHz
is possible with negligible piezoelectric response.
Series 1150 devices are compatible with FastPulse’s Laser Pulse Gating Systems. They are
used in regenerative laser amplifiers for seeding and gating, Laser Pulse Chopping and Polarization
Rotation applications. One advantage of BBO devices is that they do not induce significant
piezoelectric ringing on the transmitted laser beam.
BBO has a useful optical wavelength range from 250 nm to 2100 nm. Transmittance, in the 350 to
1100 nm range, with “V” type narrow band, high efficiency Anti-Reflection coated windows is
approximately 98.5%.
Typical intrinsic extinction ratios of single crystal BBO devices are greater than 1000:1 (>30 db)
measured at 633 nm. Single pass wavefront distortion is <1/8 wave at 633 nm. Thermal
stability is excellent over a broad temperature range. BBO crystals are slightly hygroscopic and in
many applications must be enclosed in a sealed housing. In a dry, appropriately clean, dust-free,
enclosure, all devices within the series can be used without protective windows.
The damage threshold of BBO is of the same order as deuterated KD*P and RTP, approximately 850
MW/cm2 for a 10 nanoseconds wide Q-switched pulse at 1064 nm. In gating applications with
laser pulses <100 picoseconds, the damage threshold is in the 10 GW/cm2 range.
Driving voltages required for BBO crystals to attain 1/4 or ½ wave retardation can be significantly
higher than for KD*P, Lithium Niobate and RTP crystal devices. Reduced voltage operation is
attained by use of a transverse field configuration where required drive voltage becomes a function
of crystal dimensions: the ratio of width between electrodes to overall crystal length.
The 1150 Series has an industry standard 35 mm diameter, convenient for optical mounts. The
physical size is identical with FastPulse’s Series Q1059P KD*P and 1147 RTP devices and may
easily replace them in many of the company’s E-O systems. Series 1150 devices are being used in
the company’s Models 5046, 5057 and 5100 Series Laser Pulse Extraction/ Chopping Systems,
as well as the 5048, 5056, and 5060 Q-switching Systems and 8025S HV Generator. All of these
drivers provide pulsed high voltages with zero DC voltage applied to the crystal.
