The invention also relates to a ring cavity (2,3) comprising such an optical delay circuit, and an optical interferometer (4,5) with said optical delay circuit.

The optical delay between arms of an interferometer may be provided by an optical path length difference between the arms.

The optical delay between arms of an interferometer may be different for one interferometer to that of another interferometer.

To properly work together, the apparatus and method require that the optical delay on the encryption side perfectly match the optical delay on the decryption side in both the length of delay and arrangement.

The optical delay path mirror includes a plurality of optical delay path mirrors; the purging gas supply system may direct purging gas across a face of each of the plurality of optical delay line mirrors.

The transparent substrate comprises a polymer film having an Re retardation of 10 to 70 nm, an Rth retardation of 70 to 400 nm, and a standard deviation of retardation axis angle of 1.5° or smaller.

The invention relates to a device which is used to adjust optical deceleration in a beam path, especially in a reference beam path of an OCT interferometer.

The optical compensator can include a retardation film, a c-plate, and/or a passive circuit layer.

An optical delay may be configured in a number of different ways and maybe used for delaying the encrypted optical signal.

A programmable electro-optically controlled optical delay device providing multiple optical outputs.

Measuring light from an optical delay apparatus is supplied to the Fizeau interferometer through an optical fiber.

An optical delay may be configured in a number of different ways and may be used for delaying the unencrypted optical signal.

The retardation layer is positioned with its fast optical axis at a rotation angle selected to reduce an s-polarized component of light passing through the retardation layer at a particular angle of incidence.

An optical delay may be introduced into the sampling beams before scanning.

This temporal phase modulated optical signal is then converted into a parallel optical phase signal, preferably through use of an optical delay, and modulated by an optical phase modulator.