OPTICAL-WAVEGUIDE TYPE RING LASER

摘要

PURPOSE:To obtain a structure of a single longitudinal mode optical-waveguide type laser which has excellent controllability of oscillation wavelength and a wide frequency variable range, by providing a ring resonator provided with an optical isolator, and Fabry-Perot interferometers having a specific light transmission band. CONSTITUTION:A plane substrate has on it a ring resonator 14 consisting of an optical-waveguide 12 to whose part rate earth ions of at least more than one kind are added. The ring resonator 14 is provided with an optical isolator 16, and Fabry-Perot interferometers 15 having a narrower light transmission band than a longitudinal mode frequency gap of the ring resonator 14. Therefore, highly stable oscillation operation of a single longitudinal mode laser is made possible at light transmitting frequencies of Fabry-Perot interferometers which are set to an optical wavelength within the 1.5mum band. Particularly, polarization of single laser oscillation light is made possible by arranging an optical isolator having much dependence on polarization in an appropriate direction.