Optical wavelength conversion light source

A wavelength conversion light source, comprising:

• a semiconductor laser diode device having a high reflection film applied on a rear surface thereof and an antireflection film applied on a front surface thereof;
• a lens disposed so as to be opposed to the semiconductor laser diode device;
• an optical fiber with a first Bragg grating having a first reflection bandwidth disposed in a core thereof, wherein the optical fiber has a low reflection film disposed on a light incident surface thereof, and wherein the reflectivity of the antireflection film is smaller than the reflectivity of the low reflection film;
• and
• a wavelength conversion device formed of a nonlinear optical crystal on which light from the semiconductor laser diode device is incident, wherein the optical fiber includes a second Bragg grating having a second reflection bandwidth larger than the first reflection bandwidth disposed near the first Bragg grating in said core.

A wavelength conversion light source, comprising:

• a semiconductor laser diode device;
• a lens disposed so as to be opposed to the semiconductor laser diode device;
• an optical fiber with a first Bragg grating having a first reflection bandwidth disposed in a core thereof and a second Bragg grating having a second reflection bandwidth larger than the first reflection bandwidth disposed near the first Bragg grating in said core;
• and
• a wavelength conversion device formed of a nonlinear optical crystal on which light from the semiconductor laser diode device is incident;
• wherein the semiconductor laser diode device has an antireflection film applied on a front surface thereof and oscillates in a multi-longitudinal mode, and
• wherein a distance between the semiconductor laser diode device and the first Bragg grating is set such that the multi-longitudinal mode is included in a predetermined wavelength width satisfying phase-matching conditions of the wavelength conversion device.