Q-Switched 2 Micron Solid-State Lasers and Their Applications

Abstract

In this chapter, we overview the Q-switched 2 μm solid-state laser development achieved in recent years, including flash- and diode-pumped solid-state lasers based on active and passive modulators. In summary, active Q-switching is still the first choice for obtaining large pulse energy at 2 μm currently, while passive Q-switching based on saturable absorbers (SAs), especially the newly emerging broadband low-dimension nanomaterial, is becoming promising approach in generating Q-switched 2 μm lasers specially with high repetition rate, although the output power, pulse duration, and pulse energy needs further enhancement. Besides, some important applications of 2 μm lasers, such as medicine, laser radar, and infrared directional interference, have also been introduced in brief.

High-energy, high-peak-power diode-pumped Q-switched Tm:YAG laser at 2.02 μm with tunable repetition rate from 100 Hz to 1000 Hz

“…Diode-pumped solid-state pulsed 2 µm lasers are typically based on Tm 3+ doped or Tm 3+ , Ho 3+ co-doped crystals, which have high energy storage capacity allowing for Qswitched operation [9]. These lasers can produce nanosecond laser pulses either passively, using a variety of saturable absorbers (SAs), or actively, employing acousto-optic modulators (AOMs) and electro-optic modulators (EOMs) [10].…”

“…In contrast, AOMs have high damage thresholds and ease of operation compared to EOMs, making them well-suited for generating high-energy and high-peak-power outputs with adjustable pulse repetition rates [10]. In 2017, Sato et.al reported on an AO Q-switched Tm,Ho:YLF laser operating at 2.05 µm, achieving a pulse energy of 125 mJ at 50 Hz, albeit at −80 • C [17].…”

Theoretical and experimental investigations on Nb2CT x MXene Q-switched Tm:YAP laser at 2 μm for the nonlinear optical response

“…Pulsed solid-state lasers at 2 μm have been widely applied in different applications, such as, environmental monitoring [1], medical diagnosis [2], optical communications [3], and industry microprocessing [4]. To realize a high performance solid-state laser in particular spectral region, utilizing appropriate rare-earth-ion doped laser crystal needs to be firstly investigated.…”