METHODS AND APPARATUS FOR IMPLEMENTING AN OPTICAL TRANSCEIVER USING A VAPOR CELL

• US 20200136727A1
• Filed: 10/25/2019
• Published: 04/30/2020
• Est. Priority Date: 10/26/2018
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Graceffo, Gary M., Kowalevicz, Andrew, Dolgin, Benjamin P.
• Granted Patent: US 11,349,569 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 10/25753 Distribution optical network, e.g. between a base station and a plurality of remote units
• CPC Class Codes: H04B 10/25759 Details of the reception of RF signal or the optical conversion before the optical fibre
• CPC Class Codes: H04B 10/40 Transceivers
• CPC Class Codes: H04B 2210/006 Devices for generating or processing an RF signal by optical means

Abstract

A transmitter, receiver and transceiver system that may be used for both transmitting and receiving modulated signals are disclosed. The system includes an Electrical-to-Optical (E2O) converter that receives a Radio Frequency (RF) signal and transmits an optical signal and/or an Optical-to-Optical (O2O) that performs a wavelength translation from one wavelength to another wavelength. The Electrical-to-Optical (E2O) converter includes a vapor cell that converts the RF signal to an optical signal.

Claims

1. An optical transmitter, comprising:

a probe optical source configured to provide a first optical signal;

an electromagnetic source configured to provide a modulated electromagnetic signal;

a vapor cell configured to receive the first optical signal and the modulated electromagnetic signal, the vapor cell configured to modulate the first optical signal based on the received modulated electromagnetic signal to provide a modulated output optical signal; and

launching optics configured to receive the modulated output optical signal and transmit the modulated optical signal.

2. The optical transmitter of claim 1, wherein the vapor cell comprises an Electrical-to-Optical (E2O) converter converts an electromagnetic signal to an optical signal.

3. The optical transmitter of claim 1, wherein the vapor cell comprises an Optical-to-Optical (O2O) converter that performs a wavelength translation from one wavelength to another wavelength.

4. The optical transmitter of claim 1, further comprising:

a second source of a second optical signal;

wherein the vapor cell material is opaque to a wavelength of first optical signal, and wherein the second optical signal is provided at a wavelength of light to the vapor cell to excite atoms in the vapor cell to a high principal quantum number creating a superposition of two coupled degenerative states and a dark state that is resonant with the wavelength of the first optical signal to induce electromagnetically Induced Transparency (EIT) so as to make the vapor cell transparent to the wavelength of the first optical signal.

5. The optical transmitter of claim 4, wherein the highly excited electrons of the vapor cell respond to modulation variations in the electromagnetic field, which results in a change of the transmissivity of the dark state of the vapor cell thereby causing an intensity modulation of the modulated output optical signal to be representative of a modulation of the modulated electromagnetic signal.

6. The optical transmitter of claim 1, which is part of a transceiver device that further comprises an optical Transmit/Receive (T/R) switch that routes the modulated output optical signal to one of a first output and a second output, the first output of the optical T/R switch being coupled to and providing the modulated optical signal to launching optics, the second output of the T/R switch being coupled to and providing the modulated output optical signal to an optical detector that provides a detected signal for processing.

7. A method of transmitting a modulated optical signal, comprising:

providing a first optical signal at a first wavelength;

providing a modulated electromagnetic signal;

modulating the first optical signal with vapor cell that receives the first optical signal and the modulated electromagnetic signal to provide a modulated output optical signal based on the received modulated electromagnetic signal,

launching into free space the modulated optical signal.

8. The method of claim 7, the vapor cell providing an Electrical-to-Optical (E2O) conversion.

9. The method of claim 7, the vapor cell providing an Optical-to-Optical (O2O) conversion.

10. The method of claim 7, further comprising:

providing a second optical signal to the vapor cell at a wavelength of light to excite atoms in the vapor cell to a high principal quantum number creating a superposition of two coupled degenerative states and a dark state that is resonant with the first wavelength to induce electromagnetically Induced Transparency (EIT) so as to make the vapor cell transparent to the first wavelength of the first optical signal.

11. The method of claim 10, further comprising highly exciting electrons of the vapor cell so as to respond to modulation variations in the electromagnetic field, which results in a change of the transmissivity of the dark state of the vapor cell thereby causing an intensity of modulated optical signal to be representative of a modulation of the modulated electromagnetic signal.

12. An electromagnetic receiver comprising:

a probe optical source configured to provide a first optical signal;

a vapor cell configured to receive the first optical signal and a modulated electromagnetic signal, the vapor cell configured to modulate the first optical signal based on the received modulated electromagnetic signal to provide a modulated output optical signal; and

an optical detector that receives the modulated output optical signal and provides a detected signal based on the modulated output optical signal.

13. The electromagnetic receiver device of claim 12, wherein the vapor cell comprises an Electrical-to-Optical (E2O) converter converts an electromagnetic signal to an optical signal.

14. The electromagnetic 1 receiver device of claim 12, wherein the vapor cell comprises an Optical-to-Optical (O2O) converter that performs a wavelength translation from one wavelength to another wavelength.

15. The electromagnetic receiver device of claim 12, further comprising:

a second source of a second optical signal;

wherein the vapor cell material is opaque to a wavelength of first optical signal, and

wherein the second optical signal is provided at a wavelength of light to the vapor cell to excite atoms in the vapor cell to a high principal quantum number creating a superposition of two coupled degenerative states and a dark state that is resonant with the wavelength of the first optical signal to induce electromagnetically Induced Transparency (EIT) so as to make the vapor cell transparent to the wavelength of the first optical signal.

16. The electromagnetic receiver device of claim 15, wherein the highly excited electrons of the vapor cell respond to modulation variations in the electromagnetic field, which results in a change of the transmissivity of the dark state of the vapor cell thereby causing an intensity of the modulated output optical signal to be representative of a modulation of the modulated electromagnetic signal

17. A method of receiving a modulated electromagnetic signal, comprising:

providing a first optical signal at a first wavelength to vapor cell;

receiving a modulated electromagnetic signal at the vapor cell; and

modulating the first optical signal based on the received modulated electromagnetic signal to provide a modulated output optical signal; and

detecting the modulated output optical signal and processing the detected signal to determine a modulation of the modulated electromagnetic signal.

18. The method of claim 17, further comprising the vapor cell providing an Electrical-to-Optical (E2O) conversion.

19. The method of claim 17, further comprising the vapor cell providing an Optical-to-Optical (O2O) conversion.

20. The method of claim 17, further comprising:

providing a second optical signal to the vapor cell at a wavelength of light to excite atoms in the vapor cell to a high principal quantum number creating a superposition of two coupled degenerative states and a dark state that is resonant with the first wavelength to induce electromagnetically Induced Transparency (EIT) so as to make the vapor cell transparent to the first wavelength of the first optical signal.

21. The method of claim 20, further comprising highly exciting electrons of the vapor cell so as to respond to modulation variations in the electromagnetic field, which results in a change of the transmissivity of the dark state of the vapor cell thereby causing an intensity modulation of the modulated output optical signal to be representative of a modulation of the modulated electromagnetic signal.