Submillimeter Wave Quasioptical Isolators with a Semiconductor-Based Circular Dichroic Mirror

A quasioptical isolator is studied which takes advantage of using a circular dichroic mirror for the development of a most difference between the reflection coefficients of the orthogonal circularly polarized waves. The dielectric-semiconductor and semiconductor-metal versions of the circular dichroic mirror are examined. The test show that the isolator built around the ftoroplast/n-InSb mirror makes available the wave range 0.83–1.03 mm with forward loss 2.5–3.0 dB, reverse loss 15–21 dB, and VSWR 1.02–1.14, the longitudinal magnetic field is 1.3 kGs. The isolator with the n-InSb/metal mirror covers the 0.96–1.00 mm range and offers forward loss 2.5 dB, reverse loss 20–27 dB, and VSWR less than 1.2, with the longitudinal magnetic field 0.94 kGs. A possibility of the further advancement of the devices of this kind is shown.