Abstract
Pump-probe spectroscopy in /sup 41/K by using a grating-feedback 0.77-/spl mu/m AlGaAs laser and the second-harmonic wave of a 1.54-/spl mu/m InGaAsP laser for providing a frequency reference in the 1.5 /spl mu/m region was performed. The pump laser frequency was locked to the Doppler-free resonance with frequency fluctuations less than 50 kHz estimated from the error signal. The Doppler-free absorption spectra in both co- and counter-propagating schemes were obtained, and the feasibility of simultaneous frequency stabilization and linking for two diode lasers with a frequency difference as large as 200 THz was demonstrated.