Single-frequency, injection-seeded Q-switched Ho:YAG ceramic laser pumped by a 191μm fiber-coupled LD

Abstract

A 2090 nm injection-seeded Q-switched Ho:YAG ceramic laser pumped by a 1.91 μm fiber-coupled LD is demonstrated in this paper. Single-frequency operation of Q-switched Ho:YAG ceramic laser is achieved by injection seeding technique. The maximum output energy of the single-frequency Q-switched Ho:YAG ceramic laser is 14.76 mJ, with a pulse width of 121.6 ns and a repetition rate of 200 Hz. The half-width of the pulse spectrum measured by heterodyne technique is 3.84 MHz. The fluctuation of the center frequency of the pulsed laser is 1.49 MHz (RMS) in 1 hour. As far as we know, this is the first time to report a single-frequency, injection-seeded Ho:YAG ceramic pulsed laser.

Development of Single-Longitudinal-Mode Selection Technology for Solid-State Lasers

“…In 2016, Zhang et al [59] developed the first seed-injected Ho:YAG ceramic laser using this technology. e laser used a 2.09 μm seed laser with an output pulse energy of 14.76 mJ, pulse width of 121.6 ns, and repetition frequency of 200 Hz.…”

Design and Integration of Vanadate Crystal-Based Tm and Ho Ion-Doped Gain Media for a Miniature Diode-Pumped 2.1 μm Laser

“…However, robustness of the intracavity-pumped Ho lasers is limited, due to the requirements of separate cooling to the Tm and Ho ion-doped crystals and the strict collimation between them. Hence, a more compact design for the Ho laser was proposed by diffusion-bonding the isomorphic Tm and Ho ions-doped gain media into a composite structure, which had been successfully demonstrated with the mature garnet and fluoride crystals. , However, these crystals, doped with single Tm or Ho ions, have characterized narrow pump absorption peaks and small absorption cross sections, which lead to a long gain length of above 10 mm and are not suitable for the miniaturization of Ho lasers. − Hence, an additional appealing host medium with broad and sufficiently high pump absorption is expected. Considering large absorption cross sections as well broad absorption bands of the Tm and Ho ions-doped vanadate crystals, where the peak absorption cross section around 800 nm of Tm:YVO 4 is 4 times larger than that of Tm:YAG, and the effective absorption band of Ho:YVO 4 is above 80 nm at 1.9 μm, and compact design to the Tm/Ho composite laser can be expected with the vanadate matrices.…”

High-energy, alignment-insensitive, injection-seeded Q-switched Ho:yttrium aluminum garnet single-frequency laser

“…Considering the coherent Doppler wind radar transmitter, the single-frequency laser should have a narrow linewidth, long pulse width and high energy to ensure measurement accuracy and long-range detection. The injection of seed lasers into Q-switched lasers with long cavity lengths and high energy is a proven technique for obtaining a single-frequency pulsed laser that meets the requirements [6][7][8] . Using a Q-switched Ho:YAG ring laser with six mirrors resonantly pumped by a Tm:YAG Correspondence to: Youlun Ju, National Key Laboratory of Tunable Laser Technology, Harbin Institute of Technology, Harbin 150001, China.…”