Optoelectronic oscillator and pulse generator

A pulse generator comprising an optoelectronic oscillator having an optoelectronic loop circuit, said optoelectronic loop circuit formed on a semiconductor substrate or a SiO2 substrate, said optoelectronic loop circuit comprising:

• a semiconductor laser;
• an optical waveguide guiding laser light emitted from said semiconductor laser, wherein said optical waveguide has a length on an order of centimeters;
• a photodetector detecting said laser light guided by said optical waveguide and outputting an electrical signal;
• an amplifier amplifying said electrical signal outputted from said photodetector and generating an amplified signal;
• and
• a refractive index compensation part made of a silicone resin that compensates a change of a refractive index by a temperature of said optical waveguide, wherein said refractive index compensation part has a length shorter than the length of the optical waveguide and formed in the middle of said optical waveguide,
• wherein said optoelectronic oscillator modulates said laser light emitted from said semiconductor laser by said amplified signal, and said optoelectronic oscillator generates microwave and optical pulses with a fundamental oscillation frequency determined by a delay time of said microwave and optical pulses at said optoelectronic loop circuit or a high harmonic component of integral multiples of said fundamental oscillation frequency.

A method, comprising:

• forming an optoelectric loop circuit on a semiconductor substrate or a SiO2 substrate, wherein the optoelectric loop circuit comprises a semiconductor laser, an optical waveguide guiding laser light, wherein said optical waveguide has a length on an order of centimeters, a photodetector outputting an electrical signal in response to the laser light, an amplifier generating an amplified signal, and a refractive index compensation part made of a silicone resin that compensates a change of a refractive index by a temperature of said optical waveguide, wherein said refractive index compensation part has a length shorter than the length of the optical waveguide and formed in the middle of said optical waveguide;
• modulating said laser light by said amplified signal;
• and
• generating microwave and optical pulses with a fundamental oscillation frequency determined by a delay time of said microwave and optical pulses at said optoelectronic loop circuit or a high harmonic component of integral multiples of said fundamental oscillation frequency.

An optoelectronic oscillator having an optoelectronic loop circuit, said optoelectronic loop circuit formed on a semiconductor substrate or a SiO2 substrate, said optoelectronic loop circuit comprising:

• a semiconductor laser;
• an optical waveguide with a length on an order of centimeters, wherein the optical waveguide guiding laser light emitted from said semiconductor laser;
• a photodetector detecting said laser light guided by said optical waveguide and outputting an electrical signal;
• and
• an amplifier amplifying said electrical signal outputted from said photodetector and generating an amplified signal,
• wherein said optoelectronic oscillator modulates said laser light emitted from said semiconductor laser by said amplified signal, and said optoelectronic oscillator generates microwave and optical pulses with a fundamental oscillation frequency determined by a delay time of said microwave and optical pulses at said optoelectronic loop circuit or a high harmonic component of integral multiples of said fundamental oscillation frequency,
• wherein said optoelectronic loop circuit includes a refractive index compensation part compensating a change of a refractive index by a temperature of said optical waveguide,
• wherein said refractive index compensation part includes silicone resin, is of a length shorter than said waveguide, and is formed in the middle of said waveguide.

An optoelectronic oscillator having an optoelectronic loop circuit, said optoelectronic loop circuit formed on a semiconductor substrate or a SiO2 substrate, said optoelectronic loop circuit comprising:

• a semiconductor laser;
• an optical waveguide having a core made of SiO2 buried by the SiO2, the optical waveguide guiding laser light emitted from said semiconductor laser;
• a photodetector detecting said laser light guided by said optical waveguide and outputting an electrical signal;
• and
• an amplifier amplifying said electrical signal outputted from said photodetector and generating an amplified signal,
• wherein said optoelectronic oscillator modulates said laser light emitted from said semiconductor laser by said amplified signal, and said optoelectronic oscillator generates microwave and optical pulses with a fundamental oscillation frequency determined by a delay time of said microwave and optical pulses at said optoelectronic loop circuit or a high harmonic component of integral multiples of said fundamental oscillation frequency,
• wherein a photonic crystal made of SiO2 is provided at the middle of the optical waveguide, wherein the photonic crystal decreases a group velocity of the laser light propagating in the wave guide by extending a group refractive index,
• wherein said optoelectronic loop circuit further includes a filter, and
• wherein a normalized wave number, k/(2π/a1), is 0.3 to 0.5, wherein k is a wave number of light guided in the optical waveguide and a1 is a hole interval of said photonic crystal structure in a parallel direction to the traveling direction of light.