A high energy nanosecond cryogenic cooled Yb:YAG active-mirror amplifier system

Abstract

A diode-pumped master oscillator power amplifier system based on a cryogenic Yb:YAG active-mirror laser has been developed. The performances of the laser amplifier at low temperature and room temperature have been investigated theoretically and experimentally. A maximum output energy of 3.05 J with an optical-to-optical efficiency of 14.7% has been achieved by using the master amplifier system.

Generation of 6.05J nanosecond pulses at a 1Hz repetition rate from a cryogenic cooled diode-pumped Yb:YAG MOPA system

“…shows the output energy of the Pre-amplifier versus pump energy at cooling temperature of 155K which has been verified as a proper temperature by early experiment [8]. As shown in Fig.3 (a), while the injection energy is 6 mJ, the maximum output energy of 869mJ is obtained at 1Hz corresponding to the optical-to-optical efficiency of 14.4% .…”

“…The main character of our laser system is that all the laser amplifiers are designed to active-mirror architecture for pumping and extraction architecture ( Fig.1) which has been detailed at another paper [8]. The pump beam is shaped by a group of lens focus on the end face S1.…”

The Application of Cryogenic Laser Physics to the Development of High Average Power Ultra-Short Pulse Lasers

“…Figure 46 displays the energy/pulse, repetition rate as a function of average power. Table 9 tabulates the corresponding date, energy/pulse, repetition rate, average power, pulsewidth, and reference [30,135,[147][148][149][150][151][152][153]. A number of techniques are used to generate nanosecond pulses from cryogenic amplifiers, including acousto-optic or electro-optic Q-Switching, seeded regenerative amplifiers, and in some case regenerative amplifiers followed by one or more power amplifier stages.…”

“…Two high energy/pulse, low repetition rate cryogenic nanosecond lasers have been reported in the literature. The first [151] achieved 3.05 J/pulse at 10 Hz for an average power of 30.5 W and with a 10 ns pulsewidth, using a seeded regenerative amplifier followed by active-mirror pre-amplifier and power amplifier stages. The largest energy/pulse was demonstrated in connection with the DiPOLE (Diode-Pumped Optical Laser Experiment) project [152]; 10.1 J/pulse at a 1 Hz repetition rate was obtained with a 10 ns pulsewidth and producing 10.1 W of average power.…”

A 61-mJ, 1-kHz cryogenic Yb:YAG laser amplifier*

“…[12] To achieve efficient crystal cooling, Yb:YAG is usually used as an active mirror with end pumping and end cooling. [13,14] The high gain stored in the disk crystal introduces parasitic amplified spontaneous emission (ASE). To overcome this problem, Cr:YAG is usually adopted to absorb the spontaneous light, whether diffusion bonded to the four lateral faces of Yb:YAG crystal [12] or used as interlayers in an Yb:YAG multislab amplifier.…”