Use of Co²⁺:MgAl₂O₄transparent ceramics in passive Q-switching of an Er:Glass laser at 1.534 µm

Abstract

We present the implementation of Co2+:MgAl2O4 transparent ceramics as passive Q-switching elements in an Er:Glass laser at 1.534 µm. Linearly polarized pulsed output was obtained by Brewster angle inclination of the material Q-switching plate relative to the laser axis. Separate pulses were ∼105 ns long (FWHM), exhibiting ∼6.2 kW peak power at near TEM00 quality. Several fundamental sample properties important for laser intracavity operation were measured; thermo-optic coefficient dn/dT = ( − 3.8 ± 1) × 10−5 °C−1, thermal lensing factor L−1d(nL)/dT = 2.59 × 10−5 °C−1, linear expansion coefficient α = (3.9 ± 0.6) × 10−5 °C−1, polarizability thermal coefficient ϕ = (7.2 ± 2.2) × 10−5 °C−1, and damage threshold ∼6.5 J/cm2.

Optimization of diode array side-pumped passively Q-switched Yb:Er:glass Laser

“…The Co:Spinel crystals is the most common saturable absorber for the passive Q-switch in a 1.535 µm Er-Yb:glass laser. It provides low optical loss, high absorption selection, fast recovery time (~350 ns), good thermal conductivity, and high radiation resistance [10][11].…”

Compact, diode end-pumped, eye-safe laser rangefinder transmitter

“…The passive Q-switched lasers have high peak power and nanosecond pulses. The Co:Spinel crystals has been proven to be an effective passive Q-switch in a 1.535 µm Er-Yb:glass laser 8,10,11 . It provides low optical loss in the wavelength range of 1.2 µm -1.6 µm, high absorption cross-section which permits Q-switch operation without an intracavity focusing.…”