OPTOELECTRONIC OSCILLATOR AND PULSE GENERATOR

• US 20090225799A1
• Filed: 02/06/2009
• Published: 09/10/2009
• Est. Priority Date: 02/08/2008
• Status: Active Grant

• Current Assignee: Furukawa Electric Company Limited
• Original Assignee: Furukawa Electric Company Limited
• Inventors: Hasegawa, Hideaki
• Granted Patent: US 8,031,012 B2
• Time in Patent Office: Days
• US Class Current: 372/28
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 2006/12121 Laser
• CPC Class Codes: G02B 2006/12123 Diode
• CPC Class Codes: G02B 2006/1213 comprising photonic band-gap structures or photonic lattices
• CPC Class Codes: G02B 6/1223 high refractive index type, i.e. high-contrast waveguides
• CPC Class Codes: G06F 1/04 Generating or distributing clock signals or signals derived directly therefrom
• CPC Class Codes: H01S 5/06223 using delayed or positive feedback

Abstract

The objects of the present invention are to shorten a cavity length of an optoelectronic oscillator and to integrate on a semiconductor or SiO2-substrate. An optoelectronic oscillator 10 have an optoelectronic loop comprising a semiconductor laser 11, an optical waveguide 12 guiding laser light emitted from the semiconductor laser, a photodetector 13 detecting laser light guided by the optical waveguide and outputting an electrical signal, an amplifier 14 amplifying the electrical signal outputted from the photodetector, generating an amplified signal and formed on a semiconductor substrate 15. Laser light emitted from the semiconductor laser 11 is controlled by generated amplified signal and it oscillates with a fundamental oscillation frequency determined by a delay time of carrier in the optoelectronic loop circuit or one of the high harmonic components of integral multiples of a fundamental oscillation frequency.

Claims

1. An optoelectronic oscillator having an optoelectronic loop circuit, said optoelectronic loop comprising:

a semiconductor laser;

an optical waveguide guiding laser light emitted from said semiconductor laser;

a photodetector detecting said laser light guided by said optical waveguide and an outputting electrical signal; and

an amplifier amplifying said electrical signal outputted from said photodetector, generating an amplified signal and formed on a semiconductor substrate or a SiO2-substrate,

wherein said optoelectronic oscillator modulates laser light emitted from said semiconductor laser by generated said amplified signal, and said optoelectronic oscillator generates microwave and optical pulse with a fundamental oscillation frequency determined by a delay time of microwave and optical pulse at said optoelectronic loop circuit or a high harmonic component of integral multiples of a fundamental oscillation frequency.

2. An optoelectronic oscillator according to claim 1, wherein said optical waveguide includes a clad comprising a silicon oxide film formed on a silicon substrate and a core doped with impurity and formed in said silicon oxide film.

3. An optoelectronic oscillator according to claim 1, wherein said optical waveguide comprises compound semiconductor or SiO2 formed on a compound semiconductor substrate.

4. An optoelectronic oscillator according to claim 1, wherein said optical waveguide comprises compound semiconductor or SiO2 formed on a SiO2-substrate.

5. An optoelectronic oscillator according to claim 3, wherein said compound semiconductor is InP or GaAs.

6. An optoelectronic oscillator according to claim 2, wherein said amplifier includes CMOS (Complementary Metal Oxide Semiconductor) transistor formed on said silicon substrate.

7. An optoelectronic oscillator according to claim 1, wherein said amplified signal directly modulates drive current of said semiconductor laser.

8. An optoelectronic oscillator according to claim 1, wherein said optoelectronic loop circuit further comprises an optical modulator intercalated between said semiconductor laser and said optical waveguide, and said amplified signal modulates emission light of said semiconductor laser through said optical modulator.

9. An optoelectronic oscillator according to claim 1, wherein said optoelectronic loop circuit includes a refractive index compensation part compensating a change of refractive index by temperature of said optical waveguide.

10. An optoelectronic oscillator according to claim 9, wherein said refractive index compensation part includes silicone resin.

11. An optoelectronic oscillator according to claim 1, wherein at least a part of said optical waveguide includes photonic crystal structure including semiconductor material and said optoelectronic loop circuit further includes a filter.

12. An optoelectronic oscillator according to claim 11, wherein said photonic crystal structure of said optical waveguide has group refractive index of more than 100 and is formed longer than 5 cm.

13. An optoelectronic oscillator according to claim 11, wherein high harmonic components of integral multiples of said fundamental oscillation frequency are extracted by electrical filter.

14. An optoelectronic oscillator according to claim 11, wherein said filer comprises an SG-DBR (Sampled Grating-Distributed Bragg Reflector) or a Fabry-Perot type optical filter.

15. An optoelectronic oscillator according to claim 11, wherein said filer comprises another bypass optical waveguide other than said waveguide, and said bypass optical waveguide connects an optical input port and an optical output port of said optical waveguide.

16. A pulse generator comprising An optoelectronic oscillator according to claim 1.