US 6,690,513 B2Granted

Rhomb interleaver

AssigneeJDS Uniphase Corporation

InventorsCharles Andrew Hulse, Michael R. Greenberg, Kuochou Tai

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Abstract

Interleavers are a useful tool in wavelength division multiplexing (WDM) to separate a signal with closely spaced channels into two signals, e.g. odd and even ITU channels, each with twice the channel spacing. Alternatively, two signals with a large channel spacing can be combined into a single beam with half the channel spacing. The invention relates to an optical interferometer using rhomb prisms as resonant cavities, which, when properly designed, provide the necessary phase shifts for interleaving or de-interleaving sets of optical wavelength channels. The present invention utilizes the differential phase shift between orthogonally polarized components induced by total internal reflection (TIR) off the surfaces of the rhomb prisms. Dispersion reducing techniques are also disclosed, including multiple rhomb interleavers and multi-pass rhomb interleavers.

Claims20

Dependent claims

An interferometer device comprising:

a first port for launching an input optical beam comprising first and second sets of wavelength channels;
first resonator means including:
a first reflective surface for reflecting a first portion of the input optical beam, and for transmitting a second portion of the input optical beam;
a second reflective surface for receiving the second portion of the input optical beam from the first reflective surface at an angle resulting in total internal reflection of the second portion of the input optical beam, which results in a phase shift between first and second components thereof;
a third reflective surface for receiving the second portion of the input optical beam from the second reflective surface at an angle resulting in total internal reflection of the second portion of the input optical beam, which results in a phase shift between the first and second components thereof;
and
a fourth reflective surface for receiving the second portion of the input optical signal from the third reflective surface, and for reflecting substantially all of the second portion of the input optical beam back to the first reflective surface via the second and third reflective surfaces;
whereby interference between the first and second components results in the first set of wavelength channels being out of phase with the second set of wavelength channels;
a beam splitter for separating the first set of wavelength channels from the second set of wavelength channels;
a second port for outputting the first set of wavelength channels;
and
a third port for outputting the second set of wavelength channels.

9 more elements

An interleaver device comprising:

an input port for launching an input optical beam comprising odd and even sets of signals;
beam splitting means for splitting the input optical beam into first and second sub-beams;
first Fresnel rhomb resonator means including:
a first reflective surface having a reflectivity R1 on a first end thereof, which is optically coupled to the beam splitting means, for receiving the first sub-beam, and for passing a first transmitted portion thereof;
a second reflective surface receiving the first transmitted portion at an angle resulting in total internal reflection thereof causing a phase shift between S and P components of the first transmitted portion;
a third reflective surface receiving the first transmitted portion from the second reflective surface at an angle resulting in total internal reflection thereof causing a phase shift between the S and P components of the first transmitted portion;
and
a fourth reflective surface having a reflectivity R2 on a second end thereof for reflecting substantially all of the first transmitted portion back towards the beam splitting means;
second Fresnel rhomb resonator means including:
a fifth reflective surface having a reflectivity R3 on a first end thereof, which is optically coupled to the beam splitting means, for receiving the second sub-beam, and passing a second transmitted portion;
a sixth reflective surface receiving the second transmitted portion at an angle resulting in total internal reflection thereof causing a phase shift between S and P components of the second transmitted portion;
a seventh reflective surface receiving the second transmitted portion from the sixth reflective surface at an angle resulting in total internal reflection thereof causing a phase shift between the S and P components of the second transmitted portion;
and
an eighth reflective surface having a reflectivity R4 on a second end thereof for reflecting substantially all of the second transmitted portion back towards the beam splitting means;
whereby the first and second sub-beams interfere causing the odd set of signals to be out of phase with the even set of signals;
a first output port for outputting the odd set of signals;
and
a second output port for outputting the even set of signals.

15 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/180,320Filed 27 Jun 2002 · us provisional application
Priority: 3 Jul 2001
Published: US 2003/0007157 A19 Jan 2003
Granted: 10 Feb 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

G02B 6/2713
As bulk elements, i.e. free space arrangements external to a light guide, e.g. polarising beam splitters: cascade of polarisation selective or…
G02B 6/2746
With polarisation selective and adjusting means: comprising non-reciprocal devices, e.g. isolators, FRM, circulators, quasi-isolators
G02B 6/29373
Operating principle based on material dispersion: utilising a bulk dispersive element, e.g. prism
G02B 6/29386
For multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM: interleaving or deinterleaving, i.e. separating or…