公开(公告)号：US3617764A

公开(公告)日：1971-11-02

申请号：US3617764D

申请日：1969-05-06

Applicant: BELL TELEPHONE LABOR INC

Inventor： PATEL CHANDRA K ,  TRAN NGUYEN VAN

IPC: G02F1/35 ,  G02F1/39 ,  H03F7/04

CPC classification number: G02F1/3534 ,  G02F1/39

Abstract: A phase-matched tunable millimeter wave or far infrared wave generator or mixer employs semiconductor active media having large bound-electron second-order nonlinear effects but which, in particular instances, are not sufficiently birefringent to be phase-matchable by conventional techniques. There is generated a linearly polarized difference-frequency wave for which free carriers (electrons or holes) have the effect of subtracting an appreciable amount from the index of refraction determining its propagation constant. The linearly polarized wave is generated in crystals of the active medium when the frequencies of a pair of input radiations to be mixed and a tuning condition, such as the magnitude of magnetic field applied transversely to the direction of propagation of the input radiations, are appropriately selected. Also, in a parametric oscillator, one radiation is supplied and a second radiation relatively closely spaced in frequency is highly resonated, the frequency of the second radiation and the difference frequency being variable by variation of the magnetic field magnitude.