Patent ID: 8045593

Claim:
A method of controlling a frequency-converted laser source comprising a laser cavity, an external optical feedback component, a wavelength selective component, and a wavelength conversion device, wherein: the laser cavity comprises a gain medium interposed between a relatively high reflectivity rear reflector and a relatively low reflectivity output reflector and is configured to emit light through the output reflector; the external optical feedback component is displaced from the output reflector along an optical path of the laser source and is configured to return light to the laser cavity through the output reflector by partially reflecting the emitted light; the wavelength conversion device is located along the optical path of the laser source and is characterized by a spectral acceptance curve having a full width at half maximum (FWHM); the rear reflector, the output reflector, and the external optical feedback component define available cavity modes, and the wavelength selective component ensures that laser operation can only happen in available cavity modes located within the FWHM of the wavelength conversion device; the method comprises driving a gain section of the laser cavity with a gain signal that comprises a data component and a modulation component; and the modulation component of the gain signal comprises a gain modulation amplitude I MOD that is sufficient to shift the available cavity modes in the spectral domain such that lasing at several different cavity modes sequentially is established as the gain signal is modulated, wherein: the wavelength converted output power of the lasing mode is a non-linear function of the gain signal; the gain signal is corrected to compensate for the output power non-linearity; and the gain signal is corrected by establishing the gain signal I g according to the following relation: I g =( I DATA /k ) 0.5 −I MOD where I DATA represents the data component of the gain signal, I MOD represents the modulation component of the gain signal, and k represents a constant.