Patent ID: 8922784

Claim:
A light source apparatus comprising: an optical resonator including a plurality of gain media that amplify light and an optical waveguide; and a control unit configured to individually control amplification factors of the plurality of gain media, wherein the plurality of gain media have mutually different maximum gain wavelengths whose amplification regions are mutually partially overlapped, and a wavelength at which a total gain by the plurality of gain media becomes a maximum value is set to be variable on the basis of the control on the amplification factors, wherein the light source apparatus emits light having the wavelength at which the total gain becomes the maximum value, wherein the optical resonator is a ring-type optical resonator˜ wherein the plurality of gain media is provided in series and in a state of being distant from each other, and wherein the control unit is configured to individually control a time change in the amplification factor of each gain medium according to a period of time necessary for propagating the light between each gain medium among the plurality of gain media, wherein, in a case where a sweeping period of the wavelength at which the total gain is the maximum value is set as T 1 and where a time necessary for propagating the light between each gain medium among the plurality of gain media is set as z, the control unit is configured to change the amplification factor of each of the plurality of gain media so that a phase difference in time changes in the amplification factors of successive gain media satisfies 27τ×π/T 1 .