1. A method of determining a characteristic of an input optical signal, comprising the steps of:
receiving the optical signal,
applying the optical signal to a silicon photon-counting avalanche photodiode, APD, and detecting at least two-photon absorption, TPA, the optical signal having a wavelength range extending from 1.2 \u03bcm to an upper wavelength region that increases as the number of photons simultaneously absorbed by the APD increases beyond two, and
wherein the characteristic of the optical signal being detected is a characteristic selected from a group including a signal-to-noise ratio, a group velocity dispersion, and a polarization mode dispersion.
2. A method of determining a characteristic of an input optical signal, comprising the steps of:
receiving the optical signal,
applying the optical signal to a silicon photon-counting avalanche photodiode, APD, and detecting at least two-photon absorption, TPA, the optical signal having a wavelength range extending from 1.2 \u03bcm to an upper wavelength region that increases as the number of photons simultaneously absorbed by the APD increases beyond two, and
wherein the characteristic being detected is a pulse width of the optical signal and the detected TPA count is indicative of the narrowness of the optical signal.
3. Apparatus for detecting characteristics of an input optical signal comprising
a photon-counting avalanche Photo Diode, APD, for detecting at least two-photon absorption, TPA, of the optical signal, the optical signal having a wavelength range extending from 1.2 \u03bcm to an upper wavelength region that increases as the number of photons simultaneously absorbed by the APD increases beyond two,
apparatus capable of quantifying the TPA response,
means for determining a characteristic of the optical signal using the detected TPA response,
wherein the characteristic being detected is a signal impairment of the optical signal and the detected TPA count is indicative of the signal impairment of the optical signal, and
wherein the optical signal is optical pulse communication signal and the signal impairment of the optical pulse communication signal being detected is selected from a group including a signal-to-noise ratio, a group velocity dispersion, and a polarization mode dispersion.
4. Apparatus for detecting characteristics of an input optical signal comprising
a photon-counting avalanche Photo Diode, APD, for detecting at least two-photon absorption, TPA, of the optical signal, the optical signal having a wavelength range extending from 1.2 \u03bcm to an upper wavelength region that increases as the number of photons simultaneously absorbed by the APD increases beyond two,
apparatus capable of quantifying the TPA response,
means for determining a characteristic of the optical signal using the detected TPA response, and
wherein the optical signal is optical pulse communication signal and the characteristic being detected is a pulse width of the optical pulse communication signal and the TPA rate of the APD is indicative of the narrowness of the optical pulse communication signal.
5. Apparatus for detecting characteristics of an input optical signal comprising
a photon-counting avalanche Photo Diode, APD, for detecting at least two-photon absorption, TPA, of the optical signal, the optical signal having a wavelength range extending from 1.2 \u03bcm to an upper wavelength region that, increases as the number of photons simultaneously absorbed by the APD increases beyond two,
apparatus capable of quantifying the TPA response,
means for determining a characteristic of the optical signal using the detected TPA response, and
wherein the detector apparatus is part of apparatus for real-time compensation of group velocity dispersion, GVD, and wherein the received optical signal is an optical pulse communication signal, the compensation apparatus further including
a tunable dispersion compensator for receiving the optical pulse communication signal, for providing a variable dispersion to the received optical pulse communication signal in response to a control signal, and for outputting a restored optical pulse communication signal;
a signal sampling device for sampling a predetermined portion of the restored optical pulse communication signal;
said detector apparatus detecting and counting the detected TPA rate of the restored optical pulse communication signal and for outputting a TPA count rate signal;
a control unit responsive to the TPA count rate signal for generating the control signal to the tunable dispersion compensator.
6. The GVD compensation apparatus of claim 5 being located at one or more communication units of an optical network including at a transmission unit, a repeater unit, and a receiver unit of the network.
7. Apparatus for detecting characteristics of an input optical signal comprising
a photon-counting avalanche Photo Diode, APD, for detecting at least two-photon absorption, TPA, of the optical signal, the optical signal having a wavelength range extending from 1.2 \u03bcm to an upper wavelength region that increases as the number of photons simultaneously absorbed by the APD increases beyond two,
apparatus capable of quantifying the TPA response,
means for determining a characteristic of the optical signal using the detected TPA response, and
wherein the detector apparatus is part of apparatus for real-time compensation of polarization mode dispersion, PMD, and wherein the received optical signal is an optical pulse communication signal, the compensation apparatus further including
a PMD compensator for receiving the optical pulse communication signal, for providing a variable PMD compensation to the received optical pulse communication signal in response to a control signal, and for outputting a restored optical pulse communication signal;
a signal sampling device for sampling a predetermined portion of the restored optical pulse communication signal;
said detector apparatus detecting and counting the TPA rate of the restored optical pulse communication signal and for outputting a TPA count rate signal;
a control unit responsive to the count rate signal for generating the control signal to the PMD compensator.
8. The PMD compensation apparatus of claim 7 being located at one or more communication units of a network including at a transmission unit, a repeater unit, a transceiver unit, and a receiver unit of the network.
9. Apparatus for detecting characteristics of an input optical signal comprising
a photon-counting avalanche Photo Diode, APD, for detecting at least two-photon absorption, TPA, of the optical signal, the optical signal having a wavelength range extending from 1.2 \u03bcm to an upper wavelength region that increases as the number of photons simultaneously absorbed by the APD increases beyond two,
apparatus capable of quantifying the TPA response,
means for determining a characteristic of the optical signal using the detected TPA response, and
wherein the detector apparatus is part of a signal compensation apparatus for real-time compensation of a received optical signal which is an optical pulse communication signal, the compensation apparatus further including
a first dispersion compensator for receiving a first optical pulse communication signal, for providing a variable dispersion to the received first optical pulse communication signal in response to a first control signal, and for outputting a second optical pulse communication signal;
a second dispersion compensator for receiving a second optical pulse communication signal, for providing a variable dispersion to the received second optical pulse communication signal in response to a second control signal, and for outputting a restored optical pulse communication signal;
a signal tap device for sampling a predetermined portion of the restored optical pulse communication signal;
said detector apparatus detecting and counting the TPA rate of the restored optical pulse communication signal and for outputting a TPA count rate signal;
a first control unit responsive to the TPA count rate signal for generating the first control signal to the first dispersion compensator during a first time interval;
a second control unit responsive to the TPA count rate signal for generating the second control signal to the second dispersion compensator during a second time interval;
wherein the first dispersion compensator is selected from a group including a polarization mode dispersion, PMD, compensator and group velocity dispersion, GVD, compensator; and
wherein when the first dispersion compensator is selected to be the PMD compensator, the second dispersion compensator is selected to be the GVD compensator and vice-versa.
10. Apparatus for detecting characteristics of an input optical signal comprising
a photon-counting avalanche Photo Diode, APD, for detecting at least two-photon absorption, TPA, of the optical signal, the optical signal having a wavelength range extending from 1.2 \u03bcm to an upper wavelength region that increases as the number of photons simultaneously absorbed by the APD increases beyond two,
apparatus capable of quantifying the TPA response,
means for determining a characteristic of the optical signal using the detected TPA response, and
wherein the detector apparatus is part of an autocorrelation or cross correlation apparatus for determining the autocorrelation or cross correlation between two optical signals which are optical pulse signals, the autocorrelation apparatus further including
means for producing a first and second optical pulse signals from the optical pulse communication signal, the second optical pulse signal having a controllable delay, relative to the first optical pulse signal, which is varied at a predetermined periodic rate;
said detector apparatus detecting and counting the detected TPA rate of the combined first and second optical pulse signals and for outputting a TPA count rate signal;
wherein said characteristic determining means is responsive to the TPA count rate signal for determining the autocorrelation between the first and second optical pulse signals as a function of the relative delay between the first and second optical pulse signals.
11. Apparatus for detecting characteristics of an input optical signal comprising
a photon-counting avalanche Photo Diode, APD, for detecting at least two-photon absorption, TPA, of the optical signal, the optical signal having a wavelength range extending from 1.2 \u03bcm to an upper wavelength region that increases as the number of photons simultaneously absorbed by the APD increases beyond two,
apparatus capable of quantifying the TPA response,
means for determining a characteristic of the optical signal using the detected TPA response, and
wherein the detector apparatus is part of apparatus for synchronizing a second optical pulse signal to a first optical pulse signal, the synchronizing apparatus further including
input means for receiving the first optical pulse signal;
variable delay circuit responsive to an delay adjustment signal for delaying a received second optical pulse signal by an amount determined by the delay adjustment signal to generate a delayed second optical pulse signal;
combiner for combining the first and second optical pulse signals into a combined optical signal;
said detector apparatus detecting and counting the TPA rate of the combined optical signal and for outputting a TPA count rate signal;
wherein said characteristic determining means is responsive to the TPA count rate signal and the first optical pulse signal for generating a delay adjustment signal which when applied to the variable delay circuit results in a delayed second optical pulse signal which is in synchronization with the first optical pulse signal.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A semiconductor device comprising:
a semiconductor substrate having a first surface and a second surface;
a first insulation separation region disposed on the first surface of the semiconductor substrate;
a second insulation separation region surrounded with the first insulation separation region and electrically isolated from the first insulation separation region;
a semiconductor element disposed in the second insulation separation region; and
an electrode connecting to the first insulation separation region for energizing and generating heat in the first insulation separation region.
2. The device according to claim 1, wherein
the semiconductor substrate is made of silicon.
3. The device according to claim 1, wherein
the electrode is made of aluminum, tungsten, titanium, high melting point metallic silicide or poly-crystalline silicon.
4. The device according to claim 1, wherein
the semiconductor substrate is a SOI semiconductor substrate having an embedded insulation film, and
each of the first and second insulation separation regions is disposed in a trench of the SOI semiconductor substrate, the trench which reaches the embedded insulation film.
5. The device according to claim 4, wherein
the trench corresponding to the first insulation separation region includes a plurality of insulation separation trenches.
6. The device according to claim 4, wherein
the SOI semiconductor substrate further includes a SOI layer disposed on the embedded insulation film, and
the SOI layer has an impurity concentration, which is constant in a depth direction perpendicular to the SOI semiconductor substrate.
7. The device according to claim 4, further comprising:
a second electrode, wherein
the SOI semiconductor substrate further includes a support layer disposed on the embedded insulation film and opposite to the SOI layer, and
the second electrode is disposed on the support substrate for energizing and generating heat in the support layer.
8. The device according to claim 7, wherein
the second electrode is made of aluminum, tungsten, titanium, high melting point silicide or poly-crystalline silicon.
9. The device according to claim 1, wherein
the first insulation separation region is disposed in a trench of the semiconductor substrate through a sidewall insulation film, and
the first insulation separation region is made of poly-crystalline silicon.
10. The device according to claim 1, further comprising:
a heater disposed on the second surface of the semiconductor substrate through an insulation film, wherein
the heater is made of a poly-crystalline silicon film or an aluminum film.
11. The device according to claim 1, further comprising:
a third electrode disposed on the first surface of the semiconductor substrate through an interlayer insulation film, wherein
the third electrode covers the semiconductor element through the interlayer insulation film in order to generate electric field in the interlayer insulation film.
12. The device according to claim 1, further comprising:
a second heater disposed on the first surface of the semiconductor substrate through an interlayer insulation film, wherein
the second heater is made of poly-crystalline silicon or aluminum.
13. The device according to claim 1, further comprising:
a plurality of second insulation separation regions; and
a plurality of semiconductor elements, wherein
each semiconductor element is disposed in each second insulation separation region, respectively.
14. The device according to claim 13, wherein
each semiconductor element has a same construction.
15. The device according to claim 13, wherein
at least one of the semiconductor elements is a temperature sensor, and
temperature of the first insulation separation region is controlled by a signal outputted from the temperature sensor.
16. The device according to claim 13, wherein
a part of the semiconductor elements provides a plurality of temperature sensors, and
the part of the second insulation separation regions, the part in each of which the temperature sensor is disposed, surrounds a residual part of the second insulation separation regions, the residual part in each of which the semiconductor element other than the temperature sensor is disposed.
17. The device according to claim 15, wherein
the temperature sensor is a diffusion resistor, a diode, a bipolar transistor or a MOS transistor.
18. The device according to claim 1, wherein
the semiconductor element is a gas sensor or an oscillation type element.
19. The device according to claim 1, wherein
the device is disposed on a predetermined position of a wafer, and
the device is used for an accelerated test at high temperature in order to evaluate another semiconductor element disposed on another position of the wafer.
20. The device according to claim 1, wherein
the device is used in a temperature equal to or lower than a room temperature.