A Linearly-Polarized Rubidium Vapor Laser Pumped by a Tunable Laser Diode Array with an External Cavity of a Temperature-Controlled Volume Bragg Grating

Abstract

A diode pumped alkali vapor laser has advantages in high quantum efficiency, excellent beam quality, and low thermal effect. We obtain a laser diode array (LDA) with linewidth of 0.20 nm and an external cavity of volume Bragg grating (VBG). Its central wavelength can be tuned from 779.30nm to 780.10nm by changing the VBG's temperature. Pumped by this LDA, a 2.1 W rubidium vapor laser is achieved with optical efficiency of 10.5% and slope efficiency of 22.7%.

A quasi-CW linearly polarized rubidium vapor laser pumped by a 5-bar laser diode stack

“…The slope efficiency is lower than that of the rubidium laser reported in ref [10]. In ref [10], the linewidth of the pumping light is 0.20 nm and the pressure of methane in the cell is also 79 kPa.…”

“…The linewidth matching factor is almost the same. However, the slope efficiency is no more than half of that in ref [10]. Generally, the poor mode-matching between the pumping light and the laser is responsible for the un-ideal performance.…”

“…In ref [10], the linewidth of the pumping light is 0.20 nm and the pressure of methane in the cell is also 79 kPa. The linewidth matching factor is almost the same.…”

“…Obviously, this is one of the obstacles to higher efficiency. One method to overcome this problem is adding slow axis collimators in order to collimating the LD's light in slow axis [10] . With better beamshaping of the pumping light, efficiency will be improved.…”

Simulations on flowing-gas DPALs with non-equilibrium potassium vapor

“…Until now, the way to obtain alkali vapor of all DPALs is by saturated vapor. In this way, the optimal gain zone temperature exists for DPAL output power [18], but at this temperature, the alkali vapor concentration determined by the temperature is not optimal.…”