Abstract Continuous-wave and pulsed optical parametric oscillators are disclosed in each of which the optical cavity is resonant for the idler and nonresonant for the signal. Two of the disclosed oscillators employ a nonlinear crystal placed within the pumping laser resonator; and at least one of the pump reflectors is highly transmitting for the signal radiation. One of the oscillators is designed so that oscillation may be achieved on a continuous-wave basis; the other is designed for pulsed or continuous-wave mode-locked operation in which the output consists of a train of short pulses. The other disclosed oscillator employs a nonlinear crystal in a cavity resonant for idler radiation and external to the cavity of the pumping laser. Various arrangements to affect tuning of the oscillators are disclosed.
An optical parametric oscillator comprising a body of optically nonlinear material, means for supplying electromagnetic optical pumping radiation at a fixed frequency to said body to generate by traveling wave parametric interaction signal and idler electromagnetic optical radiations of differing frequencies therein, frequency-selective means disposed about said body for resonating said idler radiation, and means for nonresonantly extracting substantially all of said signal radiation from said resonating means.
Claim 2
Dependent Claim
68 words
An optical parametric oscillator comprising a body of optically nonlinear material, means for supplying electromagnetic optical pumping radiation at a fixed frequency to said body to generate by traveling wave parametric interaction signal and idler electromagnetic optical radiations of differing frequencies therein, frequency-selective means disposed about said body for resonating said idler radiation, and means for nonresonantly extracting substantially all of said signal radiation from said resonating means.
Claim 3
Dependent Claim
32 words
An optical parametric oscillator according to claim 1 in which the ratio of the power of the pumping radiation to the threshold power of said nonlinear material is about ( pi /2)2.
Claim 4
Dependent Claim
38 words
An optical parametric oscillator according to claim 1 in which the frequency-selective resonating means comprise opposed multiple-dielectric reflectors having substantial reflectivity for the idler radiation and negligible reflectivity for the signal disposed about the body of nonlinear material.
Claim 5
Dependent Claim
56 words
An optical parametric oscillator according to claim 3 in which the means for supplying pumping radiation comprises a pumping laser including opposed reflectors forming a pump resonator, the body of optically nonlinear material being disposed within said pump resonator and in which at least one reflector of said pump resonator is highly transmitting for the signal.
Claim 6
Dependent Claim
53 words
An optical parametric oscillator according to claim 4 including means for varying the temperature of the body of optically nonlinear material to tune the parametric oscillator and including within the pump resonator means for compensating the optical path length of the pump resonator against change as a result of said change in temperature.
Claim 7
Dependent Claim
37 words
An optical parametric oscillator according to claim 4 in which the pumping laser and the frequency-selective resonating means are adapted to provide a plurality of oscillating idler modes, and including means for mode-locking said oscillating idler modes.
Claim 8
Dependent Claim
70 words
An optical parametric oscillator according to claim 3 in which the body of nonlinear material is a crystal composed of phase-matchable material, the means for supplying pumping radiation is a pulsed laser adapted to supply pumping radiation in only one direction in said crystal, and the frequency-selective resonating means includes two reflectors, the one of said reflectors farther removed from said pulsed laser being highly transmissive to the signal radiation.