Variable wavelength transceiver

• US 5,995,253 A
• Filed: 02/04/1997
• Issued: 11/30/1999
• Est. Priority Date: 02/04/1997
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Digital Equipment Corporation (HP Inc.)
• Inventors: Flaherty, Paul A.
• Primary Examiner(s): NEGASH, KINFE MICHAEL
• Application Number:
  US08/794,790
• Time in Patent Office: 1,029 Days
• Field of Search: 359/110, 359/118, 359/143, 359/152, 359/172, 359/164, 359/157, 370/344
• US Class Current: 398/36
• CPC Class Codes: H04B 10/1149 Arrangements for indoor wireless networking of information
• CPC Class Codes: H04B 10/40 Transceivers

Abstract

A variable wavelength transceiver includes a first variable wavelength transmitter, capable of generating an electromagnetic wave of a first wavelength, a second detector of an electromagnetic wave of a second wavelength, and a collision detector coupled to the second detector and the variable wavelength transmitter, the collision detector determining when the energy level of the second detector exceeds a threshold value while the variable wavelength transmitter transmits the electromagnetic wave.

Claims

1. Apparatus for communication comprising:

a first transmitter capable of generating an electromagnetic wave of a first wavelength;

a second transmitter capable of generating electromagnetic wave of a second wavelength;

a first detector for detecting electromagnetic waves of said first wavelength;

a second detector for detecting electromagnetic waves of said second wavelength; and

a collision detector coupled to the first detector and the second detector, the collision detector indicating a collision occurrence when the energy levels of both the first detector and the second detector exceed a threshold value.

2. The apparatus of claim 1 wherein the first transmitter generates electromagnetic waves of a plurality of discrete wavelengths.

3. The apparatus of claim 1 wherein the second detector detects electromagnetic waves of a plurality of discrete wavelengths.

4. The apparatus of claim 1 where the first transmitter comprises:

a first light emitting diode portion; and

a second light emitting diode portion, the first and second light emitting diode portions arranged to form an optical cavity between them.

5. The apparatus of claim 4 wherein the optical cavity is a Fabry-Perot interferometer.

6. The apparatus of claim 4 wherein the second light emitting diode portion has an imbedded electrode that can vary the conduction across the second light emitting diode portion.

7. The apparatus of claim 1 where the second detector comprises:

an optical detector; and

a thin-film variable interferometer layer coupled to the optical detector.

8. The apparatus of claim 7 where the thin-film variable interferometer layer further comprises first and second dielectric thin-film layers each having respective conductive contacts to apply charge to each respective thin-film layer to vary its dielectric constant.

9. The apparatus of claim 1 where the first and second wavelengths are in the infrared portion of the electromagnetic spectrum.