Kilohertz rate picosecond pulses amplifier for pumping of OPCPA system

Hybrid master oscillator power amplifier system providing 10 mJ, 32 W, and 50 MW pulses for optical parametric chirped-pulse amplification pumping

“…Recently, a system based upon quasi-cw pulsed Nd:YAG amplifier modules was reported producing 90 ps pulses with 130 mJ energy at subkilohertz repetition rate corresponding to 39 W average/2.0 GW peak power [15]. A system, similar to that described in this work, was reported in [16], producing 40 mJ, 48 ps, and 40 W average power with consecutive monolithic Nd:YAG amplifier stages. In this work, we describe in detail a novel system using a hybrid ultrafast/ fiber/DPSS architecture seeded by and synchronized to a sub-5-fs oscillator at kilohertz repetition rates.…”

“…A volume Bragg grating (VBG) (OptiGrate, Corp.) narrows the spectral bandwidth in the regenerative amplifier to the 10-pm-linewidth level and thereby produces a transform-limited duration of 200 ps (FWHM) similar to [20,22]. In the current configuration, the 200 ps pulse duration is seen as a trade-off, similar to other MOPA systems [1,13,16,19,23,24], between a long pulse duration (several nanoseconds) for efficient power extraction from the solid-state amplifiers and the OPCPA application with an optimum duration of less than 100 ps. This duration remains constant throughout the MOPA chain, providing the opportunity to shorten (or lengthen) the duration of the output pulses by replacing the intracavity VBG with one having a wider (or narrower) bandwidth.…”

“…Operating with picosecond pulse durations assumes high intensities in the solid-state amplifiers exceeding 1 GW∕cm 2 . For sub-100-ps pulses and good beam quality, we deem an intensity of 4 [1,16] to 6 GW∕cm 2 [23] as safe, while the damage threshold is ∼7 GW∕cm 2 for 200 ps pulses following the empirical square root scaling law [25] based upon an anticipated damage threshold of 10 J∕cm 2 for 10 ns pulses (specification from Northrop Grumman Cutting Edge Optronics). As a consequence, the operational fluences in the solid-state amplifiers are determined by the damage threshold, which is below the saturation fluence.…”

“…The anticipated output is 0.6 mJ pulse energy with 1.8 W average power at 800 nm center wavelength given 10 mJ pump energy at 1064 nm. Increasing the pulse energy from OPCPA systems beyond the millijoule level while maintaining the >1 kHz repetition rate seems feasible with our DPSS approach, in addition to the systems mentioned in [4,5,16].…”

Concepts, performance review, and prospects of table-top, few-cycle optical parametric chirped-pulse amplification

“…In this case, the average powers are sufficiently high that thermally induced lensing and depolarization must be compensated. A system has been demonstrated operating at 1 kHz with Nd:YAG amplifiers producing an output energy of 40 mJ, 48 ps duration and a corresponding average power of 40 W. 94 At higher repetition rates, a system has been presented operating with 33.7 W and 20 kHz with ∼220 ps pulse duration corresponding to 7 MW peak power. 103 Another system has been demonstrated based on Nd∶YVO 4 slab amplifier with 0.6 mJ pulse energy and 12 ps duration corresponding to an average/peak power between 46 W∕38 MW and 30 W∕50 MW.…”