Abstract: A method of optical sensing comprises coupling an excitation optical signal into a first optical fiber to induce Rayleigh backscattering, thereby providing a backscattered signal. The backscattered signal is optically amplified in the first optical fiber, thereby providing an amplified backscattered signal. The amplified backscattered signal is coupled into a second optical fiber and is optically re-amplifying in the second optical fiber.

Abstract: A method of determining perturbation of a grating formed in an optical fiber, comprises: modulating and transmitting a light beam through the optical fiber, measuring at least one phase shift in a modulation of light reflected off the grating, and determining the perturbation of the grating based on the phase shift(s).

Abstract: A method of spectroscopy, comprises: transmitting output radiation to a sample; collecting from the sample input radiation being indicative of interaction between the output radiation and the sample; modulating at least one of the output radiation and the input radiation, wherein at least one of the output radiation and the modulation is characterized by a scanned parameter; combining the input radiation, following the modulation, with a reference signal to provide a combined signal; processing the combined signal to construct a vector describing a dependence of a radiation property of the input radiation on the parameter; and at least partially identifying the sample or a change in comprises sample based on at least the vector.

Abstract: A system for providing information based on a spectral content of an optical signal, comprises: an optical modulator for applying a time-dependent modulation to the optical signal according to at least one sub-optical modulation frequency, to provide a modulated optical signal. The system also comprises an optoelectronic device configured for receiving the modulated optical signal and responsively generate an electrical sensing signal, and a signal processing system configured for processing the electrical sensing signal and to generate output correlative to at least one wavelength of the optical signal based on the modulation.

Abstract: An interferometer system comprises a sample interferometer arm for guiding a first wave to a sample, and receiving a reflected wave from the sample and a phase amplifier for amplifying a phase shift of the reflected wave, to provide phase-shift-amplified intermediate wave. The interferometer system can also comprise an additional interferometer arm for guiding an additional wave to combine with the intermediate wave, to provide an output wave, and a detector for detecting the output wave.

Abstract: A method of spectroscopy, comprises: transmitting output radiation to a sample; collecting from the sample input radiation being indicative of interaction between the output radiation and the sample; modulating at least one of the output radiation and the input radiation, wherein at least one of the output radiation and the modulation is characterized by a scanned parameter; combining the input radiation, following the modulation, with a reference signal to provide a combined signal; processing the combined signal to construct a vector describing a dependence of a radiation property of the input radiation on the parameter; and at least partially identifying the sample or a change in comprises sample based on at least the vector.

Abstract: A method of optical sensing comprises coupling an excitation optical signal into a first optical fiber to induce Rayleigh backscattering, thereby providing a backscattered signal. The backscattered signal is optically amplified in the first optical fiber, thereby providing an amplified backscattered signal. The amplified backscattered signal is coupled into a second optical fiber and is optically re-amplifying in the second optical fiber.

Abstract: A method of spectroscopy, comprises: transmitting output radiation to a sample; collecting from the sample input radiation being indicative of interaction between the output radiation and the sample; modulating at least one of the output radiation and the input radiation, wherein at least one of the output radiation and the modulation is characterized by a scanned parameter; combining the input radiation, following the modulation, with a reference signal to provide a combined signal; processing the combined signal to construct a vector describing a dependence of a radiation property of the input radiation on the parameter; and at least partially identifying the sample or a change in comprises sample based on at least the vector.

Abstract: A method of determining perturbation of a grating formed in an optical fiber, comprises: modulating and transmitting a light beam through the optical fiber, measuring at least one phase shift in a modulation of light reflected off the grating, and determining the perturbation of the grating based on the phase shift(s).

Abstract: An interferometer system comprises a sample interferometer arm for guiding a first wave to a sample, and receiving a reflected wave from the sample and a phase amplifier for amplifying a phase shift of the reflected wave, to provide phase-shift-amplified intermediate wave. The interferometer system can also comprise an additional interferometer arm for guiding an additional wave to combine with the intermediate wave, to provide an output wave, and a detector for detecting the output wave.

Abstract: A method of spectroscopy, comprises: transmitting output radiation to a sample; collecting from the sample input radiation being indicative of interaction between the output radiation and the sample; modulating at least one of the output radiation and the input radiation, wherein at least one of the output radiation and the modulation is characterized by a scanned parameter; combining the input radiation, following the modulation, with a reference signal to provide a combined signal; processing the combined signal to construct a vector describing a dependence of a radiation property of the input radiation on the parameter; and at least partially identifying the sample or a change in comprises sample based on at least the vector.

Abstract: A method of optical sensing is disclosed. The method comprises coupling an excitation optical signal into a first optical fiber to induce Rayleigh backscattering, thereby providing a backscattered signal; coupling the backscattered signal into a second optical fiber, spatially separated from the first optical fiber; and optically amplifying the backscattered signal in the second optical fiber, thereby generating a sensing signal.

Abstract: A method of optical sensing is disclosed. The method comprises coupling an excitation optical signal into a first optical fiber to induce Rayleigh backscattering, thereby providing a backscattered signal; coupling the backscattered signal into a second optical fiber, spatially separated from the first optical fiber; and optically amplifying the backscattered signal in the second optical fiber, thereby generating a sensing signal.

Abstract: A method of optical sensing is disclosed. The method comprises coupling an excitation optical signal into a first optical fiber to induce Rayleigh backscattering, thereby providing a backscattered signal; coupling the backscattered signal into a second optical fiber, spatially separated from the first optical fiber; and optically amplifying the backscattered signal in the second optical fiber, thereby generating a sensing signal.

Abstract: A method of amplifying a phase shift, comprises: receiving an input signal in response to an output signal; generating a reference signal; varying a modulation of at least one of the signals such that a ratio between modulation amplitudes of the input and reference signals is at least 0.9 and at most 1.1, and a phase difference between the reference and the input signals is from about 0.9 pi to about 1.1 pi; forming an output signal which comprises a sum of the reference and input signals, following the variation; and filtering the output signal by a bandpass filter to form a filtered output signal, wherein a bandwidth of the bandpass filter is selected such that XG<0.1, wherein X is a noise fluctuation average of the filtered output signal, and G is an expected amplification factor of a phase shift between the input and the reference signals.

Abstract: A method of amplifying a phase shift, comprises: receiving an input signal in response to an output signal; generating a reference signal; varying a modulation of at least one of the signals such that a ratio between modulation amplitudes of the input and reference signals is at least 0.9 and at most 1.1, and a phase difference between the reference and the input signals is from about 0.9 pi to about 1.1 pi; forming an output signal which comprises a sum of the reference and input signals, following the variation; and filtering the output signal by a bandpass filter to form a filtered output signal, wherein a bandwidth of the bandpass filter is selected such that XG<0.1, wherein X is a noise fluctuation average of the filtered output signal, and G is an expected amplification factor of a phase shift between the input and the reference signals.

Abstract: A method of generating a signal being phase-shifted at a predetermined phase-shift division factor relative to a reference signal is disclosed. The method comprises: using the predetermined phase-shift division factor for selecting a modulation amplitude, modulating a control signal at the selected modulation amplitude, and combining the reference signal and the control signal to form the phase-shifted.

Abstract: A method of generating a signal being phase-shifted at a predetermined phase-shift division factor relative to a reference signal is disclosed. The method comprises: using the predetermined phase-shift division factor for selecting a modulation amplitude, modulating a control signal at the selected modulation amplitude, and combining the reference signal and the control signal to form the phase-shifted.

Abstract: A method of optical sensing is disclosed. The method comprises coupling an excitation optical signal into a first optical fiber to induce Rayleigh backscattering, thereby providing a backscattered signal; coupling the backscattered signal into a second optical fiber, spatially separated from the first optical fiber; and optically amplifying the backscattered signal in the second optical fiber, thereby generating a sensing signal.

Abstract: Disclosed is a method for determining an phase spectrum ?(?) of the complex spectral transfer function H(?) of a medium. In some embodiments, the method is applied for detecting or imaging an object screened by scattering medium or for determining a refractive index spectrum of a material.