Lockheed Martin Corporation

Lockheed Martin Corpora Tion

Angus J Henderson

Yongdan Hu

Andrew Xing

Apparatus and method for high-power multi-function millimeter-wavelength (THz-frequency) signal generation using OPO and DFG in a single cavity. In some embodiments, the OPO-DFG cavity includes an optical parametric oscillator (OPO) non-linear material that receives pump light Ihaving pump-light frequency and generates two different lower intermediate frequencies of light&#x2014;an OPO-signal beam Iand a spatially/temporally overlapping OPO-idler beam I. A difference-frequency generator non-linear material then receives the two intermediate-frequency beams Iand I, and the DFG then generates a THz-frequency output signal that has a frequency equal to the difference between the two intermediate frequencies. In some embodiments, a single-piece crystal of non-linear material is used for both OPO and DFG functions. Some embodiments use a bow-tie ring having four mirrors that define the optical path: an I-beam-entry mirror, an I-light-extraction mirror to remove unconverted I-beam, an I-beam-extraction mirror, and an I-beam-extraction mirror, and a fifth I-beam-extraction mirror.

System for gigahertz to terahertz frequency signal generation using OPO and DFG

Gigahertz to terahertz frequency signal generation using OPO and DFG

High-power multi-function millimeter-wave signal generation using OPO and DFG

An optical parametric oscillator (OPO) is described that efficiently converts a near-infrared laser beam to tunable mid-infrared wavelength output. In some embodiments, the OPO includes an optical resonator containing a nonlinear crystal, such as periodically-poled lithium niobate. The OPO is pumped by a continuous-wave fiber-laser source having a low-power oscillator and a high-power amplifier, or using just a power oscillator. The fiber oscillator produces a single-frequency output defined by a distributed-feedback (DFB) structure of the fiber. The DFB-fiber-laser output is amplified to a pump level consistent with exceeding an oscillation threshold in the OPO in which only one of two generated waves ('signal' and 'idler') is resonant within the optical cavity. This pump source provides the capability to tune the DFB fiber laser by straining the fiber (using an attached piezoelectric element or by other means) that allows the OPO to be continuously tuned over substantial ranges, enabling rapid, wide continuous tuning of the OPO output frequency or frequencies.

Method and apparatus for pumping and operating optical parametric oscillators using DFB fiber lasers

An optical parametric oscillator (OPO) is described that efficiently converts a near-infrared laser beam to tunable mid-infrared wavelength output. In some embodiments, the OPO includes an optical resonator containing a nonlinear crystal, such as periodically-poled lithium niobate. The OPO is pumped by a continuous-wave fiber-laser source having a low-power oscillator and a high-power amplifier, or using just a power oscillator). The fiber oscillator produces a single-frequency output defined by a distributed-feedback (DFB) structure of the fiber. The DFB-fiber-laser output is amplified to a pump level consistent with exceeding an oscillation threshold in the OPO in which only one of two generated waves ('signal' and 'idler') is resonant within the optical cavity. This pump source provides the capability to tune the DFB fiber laser by straining the fiber (using an attached piezoelectric element or by other means) that allows the OPO to be continuously tuned over substantial ranges, enabling rapid, wide continuous tuning of the OPO output frequency or frequencies.

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Seattle, WA, United States of America

Angus J Henderson