Abstract: A laser light source includes: a resonance unit with a light emitter; and an optical negative feedback unit. The resonance unit includes: a first waveguide; a first reflector to input the reflected light to the first waveguide; a second waveguide; a second reflector connected to the second waveguide; and a ring resonator between the first waveguide and the second waveguide. The light from the first reflector is blocked from the ring resonator and partially transmitted to a first end of the first waveguide opposite to a second end connected to the light emitter and the first reflector. The optical negative feedback unit includes: a third waveguide to which the light transmitted to the first end of the first waveguide is inputted; and a third reflector connected to the third waveguide. The light from the third reflector is inputted to the first waveguide via the third waveguide.

Abstract: A laser apparatus includes: a light source configured to generate laser light; and an optical negative feedback unit configured to narrow a spectral line of the laser light using optical negative feedback. A modulation signal is input to the light source to modulate a frequency of the laser light. A modulation amount in the frequency of the laser light is detected. A modulation sensitivity is calculated from (i) the modulation amount and (ii) an intensity of the modulation signal.

Abstract: A laser apparatus includes: a light source configured to generate laser light; and an optical negative feedback unit configured to narrow a spectral line of the laser light using optical negative feedback. A modulation signal is input to the light source to modulate a frequency of the laser light. A modulation amount in the frequency of the laser light is detected. A modulation sensitivity is calculated from (i) the modulation amount and (ii) an intensity of the modulation signal.

Abstract: A laser light source includes: a resonance unit with a light emitter; and an optical negative feedback unit. The resonance unit includes: a first waveguide; a first reflector to input the reflected light to the first waveguide; a second waveguide; a second reflector connected to the second waveguide; and a ring resonator between the first waveguide and the second waveguide. The light from the first reflector is blocked from the ring resonator and partially transmitted to a first end of the first waveguide opposite to a second end connected to the light emitter and the first reflector. The optical negative feedback unit includes: a third waveguide to which the light transmitted to the first end of the first waveguide is inputted; and a third reflector connected to the third waveguide. The light from the third reflector is inputted to the first waveguide via the third waveguide.