Linewidth reduction in a large-smile laser diode array.
We present theory and simulations for a spectral narrowing scheme for laser diode arrays (LDAs) that employs optical feedback from a diffraction grating. We calculate the effect of the so-called smile of the LDA and show that it is possible to reduce the effect by using a cylindrical lens set at an angle to the beam. The scheme is implemented on a 19-element LDA with smile of 7.6 microm and yields frequency narrowing from a free-running width of 2 to 0.15 nm. The experimental results are in good agreement with the theory.
Talbot
C L
CL
Centre for Biophotonics and Laser Science, University of Queensland, Queensland 4072, Australia. talbot@physics.uq.edu.au
Friese
M E J
ME
Wang
D
D
Brereton
I
I
Heckenberg
N R
NR
Rubinsztein-Dunlop
H
H