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.