Patent ID: 6667995
Filing Date: 2003-12-23
Classification: H01S

Abstract:
An ultrashort pulse laser oscillator comprising:a laser resonator composed of two opposed mirrors forming an optical path therebetween, one of said mirrors having a predetermined transmissivity on an outgoing side, and another of said mirrors being a total reflection mirror which does not transmit light, but reflects light; a continuous wave oscillation laser for inputting excitation laser beam into said laser resonator on said optical path between said mirrors; a tunable laser medium capable of laser oscillation in a wavelength region over a predetermined range disposed in said laser resonator on said optical path between said mirrors, said tunable laser medium receiving said excitation laser beam; a photoacoustic optical crystal having birefringent property as a crystal for selecting wavelength, which is disposed in said laser resonator on said optical path between said mirrors and to which is input outgoing light from said tunable laser medium; a piezoelectric element mounted on said photoacoustic optical crystal, which is distorted in response to a frequency of voltage upon application of the voltage and inputs an acoustic wave having a frequency in response to the distortion to said photoacoustic optical crystal; a power source for applying voltage to said piezoelectric element; and a control means for controlling a frequency of voltage to be applied to said piezoelectric element by said power source; a frequency of voltage to be applied to said piezoelectric element by said power source being controlled by said control means, whereby the voltage-having a frequency conforming to a distance defined between said mirror on outgoing side and said total reflection mirror is applied to said piezoelectric element by means of said power source, besides laser beam output from said mirror on outgoing side being utilized as outgoing laser beam from said laser resonator.