High-peak power nanosecond optical parametric amplifier with periodically poled KTP

Nanoscale optical parametric amplification through super-nonlinearity induction

Optical parametric amplification (OPA) is a nonlinear process through which a low-power input wave is amplified by extracting energy from an interaction medium that is energized by a high-intensity pump wave. For a significant amplification of an input wave, a sufficiently long interaction medium is required, which is usually on the order of a few centimeters. Therefore, in the small scale, OPA is considered unfeasible, and this prevents it from being employed in micro and nanoscale devices. There have been recent studies that proposed microscale OPA through the use of micro-resonators. However, there is currently no study that has suggested high-gain nanoscale OPA, which could be quite useful for implementing nanoscale optical devices. This study aims to show that nanoscale OPA is feasible through the concurrent maximization of the pump wave induced electric energy density and the polarization density (nonlinear coupling strength) within the interaction medium, which enables a very high amount of energy to be transferred to the input wave that is sufficient to amplify the input wave with a gain factor that is comparable to those provided by centimeter scale nonlinear crystals. The computational results of our OPA model match with the experimental ones in the context of sum-harmonic generation, which is the wave-mixing process that gives rise to OPA, with an accuracy of 97.6%. The study aims to make room for further investigation of nanoscale OPA through adaptive optics and/or nonlinear programming algorithms for the enhancement of the process.

Ultrafast noncollinear optical parametric chirped pulse amplification in KTiOAsO4

Amplification of femtosecond pulses at 1.56 microm based on noncollinear parametric chirped pulse amplification in a potassium titanyl arsenate (KTA) crystal with pumping at 1.05 microm is reported. The 100 fs pulses of an erbium fiber laser are parametrically amplified while synchronously pumped by an amplified mode-locked Nd:YLF laser. This amplifier has a saturated gain of 65 dB with 30% conversion efficiency and has produced 160 fs pulses with peak powers of up to 0.75 GW. The system produced 380 mW before compression and can be readily scaled to the multiwatt range with bandwidths to support sub-100 fs pulses.

High-power optical parametric chirped-pulse amplifier system with a 1.55 microm signal and a 1.064 microm pump

We have designed and built a chirped-pulse parametric-amplifier system that utilizes a 10 Hz, 300 ps, Nd:YAG pump laser system; a 1.575 microm fiber oscillator and amplifier as the signal source; and rubidium titanyl phosphate and potassium titanyl arsenate nonlinear crystals. We obtained 260 fs, 30 mJ pulses centered at 1.550 microm, representing a gain of > 10(9) and a peak power of 100 GW. To our knowledge, these are the highest energy and peak power pulses ever produced in the 1.5-2.0 microm region

Generation of high-contrast millijoule pulses by optical parametric chirped-pulse amplification in periodically poled KTiOPO4

A new high-contrast, high-gain optical parametric chirped-pulse amplifier (OPCPA) architecture is demonstrated in periodically poled KTiOPO4 (PPKTP). This architecture overcomes parametric fluorescence contrast limitations of the OPCPA in periodically poled materials. The scheme is based on two passes of a single relay-imaged pump pulse and a free-propagating signal pulse through a 1.5 mm x 5 mm x 7.5 mm PPKTP crystal. The output energy of 1.2 mJ is generated at a center wavelength of 1053 nm by 24 mJ of pump energy. A prepulse contrast level of > 3 x 10(7) was measured with > 10(6) saturated gain in the amplifier. Amplified pulses were compressed to 200 fs. This simple and versatile concept requires only a modest pump energy from a commercial pump laser and represents a possible high-contrast front end for high-energy Nd:glass-based petawatt-class lasers.