Sensitivity of intracavity absorption measurements with Ti: sapphire laser

Abstract

Broadband emission of a Ti: sapphire laser is achieved by reduction of the spectral loss modulation resulting from the birefringence of the laser crystal. The laser emission in a 4 nm wide spectral band has been recorded at 200 μs delay after the onset of laser oscillations. The spectrum of the atmospheric absorption in the cavity of this multimode laser has been measured in the spectral range 790–830 nm. The absorption coefficients of atmospheric lines as well as the sensitivity of the measurements are estimated by dynamically recording the spectra of the laser emission. The sensitivity limit, 1.7 × 10 -8 cm -1, is the lowest obtained so far with a Ti: sapphire laser. However, it still exceeds the fundamental sensitivity limit, 10 -12 cm -1, expected for this laser.