Optical radiation detection system comprising an electric parameter measuring circuit

Patent metadata

Field	Value
Publication number	US-9722124-B2
Application number	US-201314650969-A
Country	US
Kind code	B2
Filing date	Dec 23, 2013
Priority date	Dec 21, 2012
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

An optical radiation detection system ( 100 ) comprising: an optical medium ( 1 ) structured to define a region ( 5 ) suitable for transmitting an optical radiation and being associated to at least one electric parameter varying as a function of the optical radiation concerning said region; at least one electrode ( 2, 3 ) electrically coupled to the optical medium ( 1 ), and spaced from said region ( 5 ), an electric power generator ( 4 ) connected to said at least one electrode ( 2 ) and structured to provide an electric signal (Se) to be applied to the optical medium. Further, the system comprises an electric measuring circuit ( 50 ) connected to said at least one electrode ( 2 ) and structured to provide a measuring electric signal (SM) representing a variation of said at least one electric parameter.

First claim

The invention claimed is:

1. An optical radiation detection system, comprising:
an optical medium structured to define an optical region adapted to transmit the optical radiation and being associated with at least one electrical parameter varying in accordance with the optical radiation concerning said optical region;
a first electrode and a second electrode electrically coupled to the optical medium; wherein at least one of said first and second electrodes is capacitively coupled to the optical medium and is spaced from said optical region by a dielectric material,
an electric current or voltage generator connected to said first electrode and structured to provide an electric signal to be applied to the optical medium;
an electric measuring circuit connected to said second electrode and structured to provide an electric measuring signal representing a variation of said at least one electric parameter of said optical region,
wherein the first electrode is capacitively coupled to said to the optical medium and is spaced from the optical region by a distance chosen so as to substantially reduce a disturbance in amplitude, phase, frequency and polarization of the optical radiation due to said first electrode,
wherein said distance is chosen so that an amplitude value of the electric field E(d) associated with the optical radiation which acts on said first electrode is lower than a maximum amplitude value of the electric field E 0 associated to the optical radiation which acts in said region according to the decibel relationship: R=|E 0 /E(d)| 2 >10 dB, preferably, R is higher than 20 dB, more preferably R is higher than 30 dB and most preferably R is higher than 40 dB.

2. The detection system according to claim 1 , wherein said optical medium comprises at least one of the following optical devices: waveguide, integrated waveguide, ridge integrated waveguide, rib integrated waveguide, channel waveguide, guide made using the photonic crystal technology, slot guide, guide obtained through diffusion processes, guides obtained through titanium spread in a lithium niobate crystal, semiconductor technology waveguide, silicon on insulator platform technology waveguide, indium phosphide technology waveguide, optical fibre, lithium niobate optical device, amorphous silicon optical device, AlGaAS optical device and combinations thereof with other materials, in particular those of group III-V (for example, InP), Germanium and combinations thereof with other materials, in particular those of group IV (for example Si), optical resonator, Fabry-Pérot resonator, ring resonator, a plurality of optically coupled resonators, optical interferometer, Mach-Zehnder interferometer, a wafer integrated optical circuit.

3. The detection system according to claim 1 , wherein said at least one electric parameter is related to or is at least one of the following electric quantities: an electrical resistance associated to the optical medium, an electrical capacitance associated to the optical medium, an electrical impedance associated to the optical medium, an electric voltage associated to the optical medium, an electric current associated to the optical medium, an electrical admittance associated to the optical medium.

4. The detection system according to claim 1 , wherein said first electrode and the electric signal to be applied to the optical medium are such that a ratio between a first power of an unwished disturbance optical signal due to said electric signal and a second average power of the optical radiation, measured after a propagation through said region is lower than −20 dB, preferably lower than −30 dB, more preferably lower than −40 dB, most preferably lower than −50 dB.

5. The detection system according to claim 1 , wherein the system is structured for measuring said measuring electric signal representative of a change in said at least one electric parameter depending on the optical radiation within the scope of the following applications: optical survey for measuring the amount of the optical radiation in said region, evaluating the resonance conditions of resonators, positioning for the optical fibre-guide coupling, optical wafer tests.

6. The detection system according to claim 1 , further comprising an actuator device connected to said measuring circuit and configured to change operational characteristics of the optical medium in accordance with said measuring signal.

7. The detection system according to claim 1 , wherein:
the optical medium comprises at least a further optical region adapted for transmitting the optical radiation and being associated with at least one corresponding electrical parameter varying in accordance with the optical radiation concerning the respective optical region;
the system further comprising: at least one further electrode coupled to said at least a further optical region and connected to said electric measuring circuit.

8. The detection system according to claim 1 , wherein the first and second electrode are associated with parasitic components and the electric measuring circuit is configured to extract said electric parameter independently from the parasitic components.

9. The detection system according to claim 1 , wherein said second electrode is capacitively or resistively coupled to the optical medium.

10. The detection system according to claim 9 , wherein:
said electric current or voltage generator is such that the electric signal shows a frequency allowing said electric signal to be coupled to the optical medium;
said measuring circuit is structured so as to adopt one of the following measuring techniques: current detection by synchronous detection (lock-in), techniques based on half-bridge, techniques based on bridge circuits in the raziometric splitter configuration, techniques based on full-bridge circuits, techniques based on Wheatstone bridge, techniques based on the Fast Fourier Transform, FFT, Fourier Transform, resonating techniques.

11. An optical radiation detection system, comprising:
an optical medium structured to define an optical region adapted to transmit the optical radiation and being associated with at least one electrical parameter varying in accordance with the optical radiation concerning said optical region;
a first electrode and a second electrode electrically coupled to the optical medium; wherein at least one of said first and second electrodes is capacitively coupled to the optical medium and is spaced from said optical region by a dielectric material,
an electric current or voltage generator connected to said first electrode and structured to provide an electric signal to be applied to the optical medium;
an electric measuring circuit connected to said second electrode and structured to provide an electric measuring signal representing a variation of said at least one electric parameter of said optical region,
wherein:
the optical medium comprises an interferometer and includes: a first optical branch and a second optical branch provided with respective inputs and outputs for optical radiations;
the electric measuring circuit is connected to the second electrode which is coupled to an output of the first branch and to a further second electrode which is connected to a further output of the second branch; the electric measuring circuit being structured to provide a first electric measuring signal and a second electric measuring signal, each representing electric parameter variations associated to the first branch and the second branch, respectively;
the system further comprises a differential module structured to provide a differential signal from first electric measuring signal and a second electric measuring signal.

Assignees

• Milano Politecnico

Inventors

• Melloni Andrea
• Sampietro Marco
• Grillanda Stefano
• Morichetti Francesco
• Carminati Marco
• Ferrari Giorgio

Classifications

• H01L31/08 Primary

  Electricity · mapped topic

• G02B2006/12061

  Silicon · CPC title

• G02B6/12

  of the integrated circuit kind (electric integrated circuits H10B, H10D84/00 - H10D89/00, H10F19/00, H10F39/00, H10H29/00, H10K19/00, H10K39/00, H10K59/00, H10N19/00, H10N39/00, H10N59/00, H10N69/00, H10N79/00, H10N89/00) · CPC title

• G02B2006/121

  Channel; buried or the like · CPC title

• H01L31/02325

  Electricity · mapped topic