DELAY INTERFEROMETER

• US 20090303492A1
• Filed: 06/09/2009
• Published: 12/10/2009
• Est. Priority Date: 06/10/2008
• Status: Abandoned Application

• Current Assignee: Yokogawa Electric Corporation
• Original Assignee: Yokogawa Electric Corporation
• Inventors: Hihara, Mamoru, Iemura, Koki, Asano, Junichiro
• Application Number:
  US12/481,194
• Publication Number:
  US 20090303492A1
• Time in Patent Office: Days
• US Class Current: 356/477
• CPC Class Codes: G02B 6/2861 using fibre optic delay lines and optical elements associated with them, e.g. for use in signal processing, e.g. filtering delay lines in general H03H, H01P9/00; optical computing devices G06E
• CPC Class Codes: G02B 6/29349 Michelson or Michelson/Gires-Tournois configuration, i.e. based on splitting and interferometrically combining relatively delayed signals at a single beamsplitter
• CPC Class Codes: H04B 10/677 for differentially modulated signal, e.g. DPSK signals

Abstract

In a delay interferometer in which a Michelson delay interferometer unit is mounted in a package, the delay interferometer includes: a Michelson delay interferometer unit in which A-channel interference output light obtained by optically processing input light that is formed by splitting input light received through an input port, into A and B channels through a splitting portion is output from an A-channel first output port and an A-channel second output port disposed, and B-channel interference output light is output from a B-channel first output port and a B-channel second output port; and a first optical path length compensating member which is interposed between the A-channel interference output light or the B-channel interference output light, and the A-channel first output port or the B-channel first output port.

Claims

1. A delay interferometer comprising:

a package including an input port through which input light is received, an A-channel first output port and an A-channel second output port, through which output an A-channel interference output light, and a B-channel first output port and a B-channel second output port, through which output a B-channel interference output light;

a Michelson delay interferometer unit mounted in the package, the Michelson delay interferometer unit including a splitting portion which splits the input light into A and B channels in such a manner that there is an optical path length difference between the A-channel interference output light and the B-channel interference output light, the Michelson delay interferometer unit optically processing the split lights as an input light to form the A-channel interference output light and the B-channel interference output light; and

a first optical path length compensating member which is interposed between the A-channel interference output light or the B-channel interference output light, and the A-channel first output port or the B-channel first output port.

2. A delay interferometer according to claim 1, further comprising:

a second optical path length compensating member which is interposed between the A-channel interference output light or the B-channel interference output light, and the A-channel second output port or the B-channel second output port.

3. A delay interferometer according to claim 1, wherein the first optical path length compensating member is a rectangular prism.

4. A delay interferometer according to claim 2, wherein the first optical path length compensating member and the second optical path length compensating member are rectangular prisms.

5. A delay interferometer according to claim 1, wherein the Michelson delay interferometer unit includes a beam splitter and reflectors which are integrally structured by a same material.