Patent attributes
A wavelength variable laser smaller in size than the conventional one can be achieved by arranging a gain chip, an etalon filter and a fifth reflective mirror on an AlN submount and longitudinally integrating the gain chip in which a 45° mirror and a lens are integrated and the etalon filter. A laser cavity has a structure in which light passes through an active layer from a first reflective mirror realized by an end surface of the gain chip, is reflected by the 45° mirror at an angle of 90° and then passes through the lens. The light having passed through the lens is converted into parallel light, passes through the etalon filter and reaches the fifth reflective mirror and is then reflected. The reflected light returns through the same optical path and reaches the first reflective mirror realized by the end surface of the gain chip.
