The laser system is a Continuum Powerlite 9010, which is Nd:YAG, Q-switched by a Pockels’ cell producing a 7ns (FWHM) pulsewidth operating at a 10 Hz repetition rate.  It is injection seeded with a diode laser to maintain a single longitudinal mode.  This laser can be frequency-doubled to 532nm using a Type I KDP crystal, which reduces the pulsewidth to 5ns (FWHM), or frequency-tripled (355nm) using a second Type I KDP crystal for pumping an optical parametric oscillator (OPO).

• Pulse Energy: 2 J
• Pulse Width: 5 – 9 ns
• Maximum Average Power: 20 W
• TBWP: close to transform limited
• Repetition Rate: 10 Hz
• Polarization: Linear, horizontal
• Energy Stability: 2.5 % rms
• Beam Diameter: 9 mm ± 1 mm
• Beam Divergence: 450 µradians
• Transverse Mode: TEM₀₀ ( > 1 m from output)

Continuum Lasers

The OPO is a Continuum Sunlite EX, which uses BBO as the nonlinear crystal.  There are also two BBO single-pass optical parametric amplifiers (OPA) that increase the output power.  The OPO beam is spatially filtered both intracavity and externally to obtain a profile most resembling a Gaussian shape.  The OPO signal beam is tunable from 450nm to 710nm, and its pulsewidth is 3-4ns (FWHM). The idler beam is then tunable from 710nm to 1682nm.

• Pump Energy (355 nm): 350 mJ
• Pulse Width: 3-6 ns
• Repetition Rate: 10 Hz
• Tuning Range: 445 nm – 1750 nm
• Pulse Energy: 50 mJ (at peak)
• Polarization: vertical
• Beam Diameter: 4-6 mmv
• Beam Divergence: < 1.5 mrad
• Energy instability: 10%v
• Spatial Profile: Gaussian