US4761050A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical switching device including polarization preserving coupler utilizing Kerr effect and method of using same
Assignee: STC PLC
•
Filing: 1987-05-28
•
Granted: 1988-08-02
•
Expires: 2007-05-28
Abstract
Abstract An optical crossbar switch employs the optical Kerr effect to cause switching of an input signal between two possible outputs. In the absence of a pump signal the output is on one fibre. In the presence of a pump signal the output is on the other fibre. The pump signal serves to produce rotation of the polarization of the input signal in a polarization maintaining coupler, the two possible polarization states being separated by a birefringent crystal or a polarization selective beam splitter.
Inventors
- 👤 Kevin C. Byron
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:58
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/35; G02F1/3515
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
104 words
An optical switch comprising an input for an optical signal, an input for a pump optical signal and first and second outputs, a polarisation maintaining coupler to which the two inputs are coupled and means for spatially separating two polarisation states disposed intermediate an output of the coupler and the first and second outputs, wherein in the absence of the pump signal said optical signal is coupled to the first output and wherein in the presence of a pump signal rotation of the polarisation of said optical signal is caused and the optical signal with the rotated polarisation state coupled to the second output.
Claim 2
Dependent Claim
104 words
An optical switch comprising an input for an optical signal, an input for a pump optical signal and first and second outputs, a polarisation maintaining coupler to which the two inputs are coupled and means for spatially separating two polarisation states disposed intermediate an output of the coupler and the first and second outputs, wherein in the absence of the pump signal said optical signal is coupled to the first output and wherein in the presence of a pump signal rotation of the polarisation of said optical signal is caused and the optical signal with the rotated polarisation state coupled to the second output.
Claim 3
Dependent Claim
21 words
An optical switch as claimed in claim 1, wherein the means for spatially separating two polarisation states includes a birefringent crystal.
Claim 4
Dependent Claim
25 words
An optical switch as claimed in claim 1, wherein the means for spatially separating two polarisation states is comprised by a polarisation selective beam splitter.
Claim 5
Independent Claim
105 words
A method of switching an input optical signal between either of two outputs, comprising the steps of applying the input optical signal to a polarisation maintaining coupler to which can be input a pump optical signal and applying the output of the coupler to means for spatially separating two polarisation states, whereby in the absence of the pump optical signal the coupler output is applied to one said output and in the presence of the pump optical signal rotation of the polarisation of the input optical signal is caused and the optical signal with the rotated polarisation state is applied to the other said output.
Claim 6
Independent Claim
105 words
A method of switching an input optical signal between either of two outputs, comprising the steps of applying the input optical signal to a polarisation maintaining coupler to which can be input a pump optical signal and applying the output of the coupler to means for spatially separating two polarisation states, whereby in the absence of the pump optical signal the coupler output is applied to one said output and in the presence of the pump optical signal rotation of the polarisation of the input optical signal is caused and the optical signal with the rotated polarisation state is applied to the other said output.
Claim 7
Dependent Claim
28 words
A method as claimed in claim 4 including the step of applying the output of the coupler to a birefringent crystal for spatially separating said two polarisation states.
Claim 8
Dependent Claim
30 words
A method as claimed in claim 4 including the step of applying the output of the coupler to a polarisation selective beam splitter for spatially separating said two polarisation states.
References Cited (Backward Citations)
US3611231A
Cited
US3914710A
Cited
US4265543A
Cited
US4331387A
Cited
US4720162A
Cited
US4720160A
Cited
US4441186A
Cited
JPS58205102A
Cited
US4515431A
Cited
JPS5978322A
Cited
US4546476A
Cited
US4554510A
Cited
US4553238A
Cited
US4723824A
Cited
US4591372A
Cited
US4644556A
Cited
JPS60242435A
Cited
GB2170920A
Cited
US4694243A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-02 | 1992-02-01 | 1992-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-02 | 1996-02-01 | 1996-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-02 | 2000-02-01 | 2000-08-02 | $7700.00 | Window Closed / Lapsed |