Coherent properties of FBG-based external cavity diode lasers

Coherent poperties and fine tuning of two FBG-based external cavity diode lasers were investigated. The external cavity length of each laser was as short as 10 mm. The linewidth was measured to be as narrow as several tens of kHz*m W and side mode suppression ratio of 30 dB was obtained. The tuning rate was measured to be 1MHz/mA that is three orders of magnitude less than typical value of injection lasers. The operating regime, in which tuning rate equals to zero, was observed. This fact makes FBG-based external cavity diode lasers very attractive for fine interferometric applications.