Features

• Ultra-wide spectral range of 210 nm to 16 000 nm
• High peak power (>50 MW) ideal for non-linear spectroscopy applications
• Narrow linewidth
• Motorized hands-free tuning in 210 – 2300 nm or 420 nm – 10 000 nm range
• Remote control via keypad
• PC control via USB port (RS232 is optional) and LabView™ drivers

Applications

• Nonlinear spectroscopy: vibrational-SFG, surface-SH, CARS, Z-scan
• Pump-probe experiments
• Laser-induced fluorescence (LIF)
• Other laser spectroscopy applications

Travelling wave optical parametric generators (TWOPG) are an excellent choice for researchers who need an ultra-fast tunable coherent light source from UV to mid IR.

EKSPLA offers four models designed for pumping by up to the 4th harmonic of Nd:YAG laser.

PG401 model has a tuning range of 420 nm to 2300 nm and is optimized for providing highest pulse energy in the visible part of the spectrum. When combined with an optional second harmonic generator (SHG) or Difference Frequency Generator (DFG) stages, it offers the widest possible tuning range – from 210 nm to 16 000 nm. The wide tuning range makes PG401 units suitable for virtually any spectroscopy application.

PG501 model has a tuning range of 680 to 2300 nm and highest pulse energy in the near-IR spectral range. Optional DFG stages are available for extension of tuning range to the 2300 ‑16 000 nm region. The PG501-DFG1P model is probably the optimal choice for vibrational-SFG spectroscopy setups.

PG601 model has a tuning range of 320 to 500 nm and 580 to 1580 nm and is targeted for LIF applications.

PG701 model has a tuning range of 1400 to 4500 nm and is targeted for vibrational-SFG or infrared spectroscopy applications.

Design

The units can be divided into several functional modules:

• optical parametric generator (OPG);
• diffraction grating based linewidth narrowing system (LNS);
• optical parametric amplifier (OPA);
• electronic control unit.

The purpose of the OPG module is to generate parametric superfluorescence (PS). Spectral properties of the PS is determined by the properties of a nonlinear crystal and usually varies with the generated wavelength.

In order to produce narrowband radiation, the output from OPG is narrowed by LNS down to 6 cm-1 and then used to seed OPA.

Output wavelength tuning is achieved by changing the angle of the nonlinear crystal(s) and grating.

To ensure exceptional wavelength reproducibility, precise stepper motors driven by a computerized control unit rotate the nonlinear crystals and diffraction grating. Nonlinear crystal temperature stabilization ensures long-term stability of the output radiation wavelength.

In order to protect nonlinear crystals from damage, the pump pulse energy is monitored by built-in photodetectors, and the control unit produces an alert signal when pump pulse energy exceeds the preset value.

For customer convenience the system can be controlled through its USB type PC interface (RS232 is optional) with LabView drivers or a user-friendly remote control pad. Both options allow easy control of system settings.