Amplification-free electro-optical oscillator

Patent metadata

Field	Value
Publication number	US-9768873-B2
Application number	US-201414489393-A
Country	US
Kind code	B2
Filing date	Sep 17, 2014
Priority date	Sep 17, 2013
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

An electro-optical oscillator includes, in part, a modulator, a signal splitter, N photodiodes with N being an integer greater than one, a signal combiner, and a filter. The modulator modulates an optical signal in accordance with a feedback signal. The splitter splits the modulated optical signal into N optical signals each delivered to a different one of N photo-diodes. Each of the N photo-diodes converts the optical signal it receives to a current signal. The signal combiner combines the N current signals received from the N photo-diodes to generate a combined current signal. The filter filters the combined current signal and generates the feedback signal. The electro-optical oscillator optionally includes, in part, N variable optical gain/attenuation components each amplifying/attenuating a different one of the N optical signals generated by the splitter.

First claim

What is claimed is:

1. An electro-optical oscillator comprising:
an optical modulator adapted to generate a pair of modulated differential optical signals from a received optical signal;
a splitter adapted to split the modulated differential optical signals into a first N differential optical signals and a second N differential optical signals, the splitter delivering each of the first N optical signals to a different one of first N optical paths, and delivering each of the second N optical signals to a different one of second N optical paths, N being an integer greater than one;
a first N photo-diodes each adapted to convert a different one of the first N optical signals to a current signal;
a second N photo-diodes each adapted to convert a different one of the second N optical signals to a current signal;
a first signal combiner adapted to combine the N current signals received from the first N photo-diodes to generate a differentially positive signal;
a second signal combiner adapted to combine the N current signals received from the second N photo-diodes to generate a differentially negative signal;
a first filter adapted to filter the differentially positive signal to generate a first feedback signal; said first filter adapted to apply the first feedback signal to the optical modulator; and
a second filter adapted to filter the differentially negative signal to generate a second feedback signal; said second filter adapted to apply the second feedback signal to the optical modulator.

2. The electro-optical oscillator of claim 1 further comprising:
first N variable optical gain/attenuation components each disposed in a different one of the first N optical paths and adapted to amplify/attenuate the optical signal delivered to the path; and
second N variable optical gain/attenuation components each disposed in a different one of the second N optical paths and adapted to amplify/attenuate the optical signal delivered to the path.

3. The electro-optical oscillator of claim 2 further comprising:
first N variable delay components each disposed in a different one of the first N optical paths and adapted to delay the optical signal delivered to the path; and
second N variable delay components each disposed in a different one of the second N optical paths and adapted to delay the optical signal delivered to the path.

4. The electro-optical oscillator of claim 1 further comprising:
first N variable delay components each disposed in a different one of the first N optical paths and adapted to delay the optical signal delivered to the path; and
second N variable delay components each disposed in a different one of the second N optical paths and adapted to delay the optical signal delivered to the path.

5. The electro-optical oscillator of claim 1 further comprising:
at least one variable delay component disposed between the optical modulator and the splitter and adapted to delay the optical signal delivered to the splitter.

6. A method of generating an oscillating signal, the method comprising:
modulating an optical signal to generating a pair of modulated differential signals;
splitting a first one of the pair of modulated differential signals into a first N differential optical signals each delivered to a different one of first N optical paths;
splitting a second one of the pair of modulated differential signals into a second N differential optical signals each delivered to a different one of second N optical paths;
converting the optical signal delivered to each of the first N optical paths to generate a first N current signals;
converting the optical signal delivered to each of the second N optical paths to generate a second N current signals;
combining the first N current signals to generate a differentially positive current signal;
combining the second N current signals to generate a differentially negative current signal;
filtering the differentially positive current signal to generate a first feedback signal;
filtering the differentially negative current signal to generate a second feedback signal;
modulating the optical signal in accordance with the first feedback signal to generate the first one of the pair of modulated differential signals; and
modulating the optical signal in accordance with the second feedback signal to generate the second one of the pair of modulated differential signals.

7. The method of claim 6 further comprising:
amplifying/attenuating the optical signal delivered to each of the first and second N optical paths.

8. The method of claim 7 further comprising:
delaying the optical signal delivered to each of the first and second N optical paths.

9. The method of claim 6 further comprising:
delaying the optical signal delivered to each of the first and second N optical paths.

10. The method of claim 6 further comprising:
delaying the pair of modulated differential signals prior to splitting the pair of modulated differential signals.

Assignees

• California Inst Of Techn

Inventors

• Hajimiri Seyed Ali
• Aflatouni Firooz
• Abiri Behrooz

Classifications

• H04B2210/006

  Devices for generating or processing an RF signal by optical means · CPC title

• H04B10/50 Primary

  Transmitters · CPC title

• H04B10/50577 Primary

  to control the phase of the modulating signal · CPC title

• H04B10/90

  Non-optical transmission systems, e.g. transmission systems employing non-photonic corpuscular radiation · CPC title