US 4,390,236 A · Tunable polarization independent wavelength filter

Abstract

Tunable, polarization independent wavelength filtering is obtained in a circuit configuration comprising an input polarization selective coupler which separates the TM and TE mode waves. A first, wavelength selective mode converter, in the TE mode wavepath, converts the TE mode wave energy at the selected wavelength to the TM mode. Similarly, a second wavelength selective mode converter, located in the TM mode wavepath, converts the TM mode wave energy at the selected wavelength to the TE mode. An output polarization selective coupler combines the TE and TM mode wave energy at the selected wavelength in one output wavepath and combines the balance of the input signal in a second wavepath. By cascading a plurality of such circuits, each tuned to a different wavelength, a wavelength multiplexed signal can be demultiplexed.

Claims5

Dependent claims

A wavelength filter (10) comprising:

an input polarization selective coupler (11) for separating, in two different wavepaths (12, 13), orthogonally polarized wave components (TE, TM) of an arbitrarily polarized input signal;
a wavelength selective (TE.revreaction.TM) mode converter (14, 15) located in each of said wavepaths (12, 13);
and an output polarization selective coupler (16) for combining in one output signal path (17) signal components centered about the wavelength of said mode converters, and for combining in a second output wavepath (18) the balance of said input signal.

Dependencies are inferred from the claim text.

Tunable polarization independent wavelength filter

Life of this patent

Tunable polarization independent wavelength filter

Life of this patent

Abstract

Claims5