Increasing the output of a Littman-type laser by use of an intracavity Faraday rotator

Abstract

We present a new method of external-cavity diode laser grating stabilization which combines the high output power of the Littrow design with the fixed output pointing of the Littman-Metcalf design. Our new approach utilizes a Faraday-effect optical isolator inside the external cavity. Experimental testing and a model which describes the tuning range and optimal tuning parameters of the laser are described. Preliminary testing of this design has resulted in a short-term linewidth of 360 kHz and a side-mode suppression of 37 dB. The laser tunes mode-hop free over 7 GHz and we predict that much larger tuning ranges are possible.