Non‐collinear optical parametric amplifier for time‐resolved broadband picosecond CARS

Abstract

We demonstrate generation of broadband high‐intensity picosecond pulses using a non‐collinear optical parametric amplifier, seeded with a broadband cavity‐less dye laser and pumped using the second harmonic of a picosecond Nd:YAG laser. With appropriate choice of the pump‐seed non‐collinearity angle, we observed energy conversion from the pump to the signal wave of around 15%, with the bandwidth of the amplified radiation around 445 cm−1 (20.7 nm) centered around 680 nm. An energy of 1.2 mJ per pulse of duration around 26 ps has been achieved. A light source with such parameters could be suitable for use in time‐resolved broadband picosecond Coherent anti‐Stokes Raman scattering. Copyright © 2014 John Wiley & Sons, Ltd.

Broadband noncollinear optical parametric amplification under low‐frequency picosecond pump in homogeneous KTP crystal

“…Based on these measurements, as well as on the calculations of the phase‐matching curves of KTP for the main parametric process and on the geometry of the noncollinear phase matching (Figure ), we can conclude the following. The horizontal plane passing through the positions “3 o'clock” and “9 o'clock” and coinciding with the plane ZOX of the crystal is a plane of symmetry for the light cone, because the vertical projections of the generatrix of cone onto the plane ZOX from cone's upper and lower parts form the same angles both with the pump wavevector and with the Z ‐axis of the crystal.…”

“…Initially, we have developed the NOPA as a light source for the time-resolved broadband picosecond CARS. [18] This CARS technique is based on the fact that the nonresonant contribution to the full CARS signal decays faster than the resonance contribution, and under some delay, it is possible to find a compromise between the magnitude of the nonresonant contribution and the ability to register the total signal, which decreases, with increasing delay of CARS probing, to the level of the detector noise or electronics noise. The ability to amplify optically a weak anti-Stokes signal before it comes to the detector would significantly expand the range of delays when working with the time-resolved broadband picosecond CARS.…”

Recent advances in linear and non‐linear Raman spectroscopy. Part IX

“…describe the details of a non‐collinear optical parametric amplifier for time‐resolved broadband picosecond CARS. This techniques involved seeding with a broadband cavity‐less dye laser and pumped using the second harmonic of a picosecond Nd:YAG laser . Zhao and colleagues probed the vibrational characteristics in ethanol using spectrally dispersed femtosecond CARS.…”

Advances in nonlinear optical spectroscopies: a historical perspective of developments and applications presented at ECONOS

“…On the other hand, only a few articles on instrumental developments have been published in the ECONOS special issues. Vereshchagin et al presented a non‐collinear parametric amplifier for the generation of broadband laser pulses in the picosecond regime. This device is a useful alternative to dye lasers in CARS experiments.…”