Diode lasers can be tuned by simultaneous rotation and translation of an external grating. This can be achieved by rotating the grating about a displaced pivot point. We derive the tuning range as a function of pivot point position for various extended cavity geometries. In each case, the geometric problem reduces to the solution of a quadratic equation. For near-infrared wavelengths, placement of the pivot is relatively noncritical for tuning ranges of the order of 10 GHz, but requires millimeter accuracy for a tuning range >100 GHz.
© 1999 Optical Society of America
(050.2770) Diffraction and gratings : Gratings
(140.2020) Lasers and laser optics : Diode lasers
(140.3410) Lasers and laser optics : Laser resonators
(140.3600) Lasers and laser optics : Lasers, tunable
Lars Nilse, Hillary J. Davies, and Charles S. Adams, "Synchronous Tuning of Extended Cavity Diode Lasers: The Case for an Optimum Pivot Point," Appl. Opt. 38, 548-553 (1999)