Energy scaling of nanosecond gain-switched Cr²⁺:ZnSe lasers

Abstract

In this paper, we report record nanosecond output energies of gain-switched Cr:ZnSe lasers pumped by Q-switched Cr:Tm:Ho:YAG (100 ns @ 2.096 μm) and Raman shifted Nd:YAG lasers (7 ns @ 1.906 μm). In these experiments we used Brewster cut Cr:ZnSe gain elements with a chromium concentration of 8x10 18 cm -3 . Under Cr:Tm:Ho:YAG pumping, the first Cr:ZnSe laser demonstrated 3.1 mJ of output energy, 52% slope efficiency and 110 nm linewidth centered at a wavelength of 2.47 µm. Maximum output energy of the second Cr:ZnSe laser reached 10.1 mJ under H 2 Raman shifted Nd:YAG laser pumping. The slope efficiency estimated from the input-output data was 47%.

Mid-infrared diode pumped Cr: ZnSe laser continuously tunable from 2.1 μm up to 2.7 μm operated at room temperature

“…A relatively high unfavorable thermal lensing parameter is compensated by the low thermal load due to the mentioned absence of such parasitic processes as ESA or up-conversion. The possibility of Cr:ZnSe compact laser system direct excitation by laser diodes 4,[7][8][9][10][11] or thulium fiber lasers [12][13][14] have been reported together with various modes of laser operation, including continuous wave (CW) [7][8][9][14][15][16] , free-running 17 , gain-switched 16,18,19 , Q-switched [20][21][22] , and mode-locking 21,[23][24][25][26] regimes.…”

Short-pulsed gain-switched Cr2+:ZnSe laser

“…A detailed review of the progress made in fabrication of A II B IV compounds doped by transition metal impurities was performed by S Mirov and presented in [22,23]. Cr:ZnSe lasers can operate in continuous wave (cw) [24][25][26] or pulse [23,27,28] mode. An elegant method of ns pulse generation is gain-switching where pulse operation is obtained by laser gain on/off switching via pump power modulation.…”

“…As can be seen in table 1, Cr:ZnSe lasers providing pulses with 20 mJ output energy and corresponding peak power of over 1.3 MW have already been developed. Analyzing the literature reports, one can also note that despite the high pulse peak power achieved [23,27], the shortest pulse width is reported to be 7 ns and there has been no discussion on its further shortening.…”