High-accuracy laser-wavelength detection using a synchro-scanned optical disk filter

A simple laser-wavelength detection method is presented based on time-domain signal analysis using a continuously tunable, wide-band synchro-scanned optical disk filter. A differential signal is defined between two light powers monitored ground the time corresponding to the laser wavelength of interest to detect the slight wavelength deviation. A maximum detection accuracy of /spl plusmn/100 MHz has been achieved using a filter with a 3-dB width of 0.83 nm.