285 mJ Electro-optically -switched Er:YAG Master Oscillator Power Amplifier (MOPA) System with Adjustable Pumping Delay between Flashlamps at 2.94

• Published in: Current optics and photonics Vol. 7; no. 3; pp. 297 - 303
• Main Authors: Heesuk Jang, Hajun Song, Hae Seog Koh, Han Young Ryu
• Format: Journal Article
• Language: Korean
• Published: 2023
• Subjects: Er:YAG laser; Flashlamp pumping; Mid-infrared; Electro-optic ${\mathcal{Q}}$-switching
• ISSN: 2508-7266; 2508-7274

In this paper, we demonstrated a high-energy (285 mJ) mid-infrared flashlamp-pumped electro-optically -switched Er:YAG master oscillator power amplifier (MOPA) system and comprehensively investigated its temporal, spectral, and spatial characteristics. To increase the output energy, we optimized the delay between the timings at which the flashlamps of the master oscillator and power amplifier were triggered. In addition, the output energy was improved while minimizing thermal effects by cooling the MOPA system to a temperature slightly above the dew point. Consequently, the MOPA structure boosted the output energy without damaging the lithium niobate Pockels cell, which is a crucial element in -switching. This design realized pulses with energies up to 0.285 J and pulse durations of approximately 140 ns at a wavelength of 2,936.7 nm. This high-energy mid-IR Er:YAG MOPA system can be used for various scientific, engineering, and military underwater applications.