Abstract: An integrated optical circuit includes a first device and a second device, which devices are connected by a polarization convertor. The polarization convertor includes a curved section of a waveguide, integrated in the optical circuit. The curved section may have several differently curved subsections. The conversion ratio is determined in part by the radius of curvature of the curved subsections as well as by the number of transitions between subsections.

Abstract: An integrated optical circuit comprises a first device and a second device, which devices are connected by a polarization convertor. The polarization convertor has one or more curved sections of a waveguide, integrated in the optical circuit. The conversion ratio is determined in part by the radius of curvature of the curved sections.

Abstract: An arrangement for polarization control for an optical heterodyne or homodyne receiver wherein the state of polarization of the optical signal of the local oscillator of a heterodyne or homodyne receiver and the optical signal supplied to the receiver can be transformed so that both signals can be adjusted to the same identical state of polarization. A phase modulator PM1 and a following polarization converter PK1 are arranged onto an optical waveguide WL1 which receives at an input e.sub.1 an optical wave from a subscriber and another polarization converter PK2 and a following phase modulator PM2 are arranged onto another optical waveguide WL2 which has an input e.sub.2 for coupling in the local oscillator signal. The arrangement can be controlled such that the signals fed in have the same state of polarization at the output for superposition and IF generation.

Abstract: Apparatus for continuous reset-free polarization and phase control which includes an optical strip waveguide 10 in which two waves TE and TM mode are polarized orthogonally relative to each other and have mutually different propagation constants .beta..sub.1 and .beta..sub.2 and includes a plurality of N=4m equidistant electrodes (E.sub.i, where i=1, 2 . . . N) which are mounted successively along the strip waveguide 10 and where m is a whole number between 5 and 10 and wherein each electrode E.sub.i receives a voltageU.sub.i =U.sub.0 sin (.eta.+(i-1).multidot..pi..multidot..LAMBDA..sub.0 /2.multidot..LAMBDA..sub.1) with i=1, 2, . . . Nwherein .LAMBDA..sub.0 is the geometrical length fixed by four electrodes and .LAMBDA..sub.1 is the length defined by the operating wavelength .LAMBDA..sub.1 and .eta. is a variable control quantity between and 0 and 2.pi. and U.sub.0 is a variable maximum voltage.