Abstract: In some embodiments, an apparatus includes a quadrature amplitude modulation (QAM) optical modulator which includes a first phase modulator (PM), a second PM, a tunable optical coupler (TOC), and an optical combiner (OC). The TOC is configured to split a light wave at an adjustable power splitting ratio to produce a first split light wave and a second split light wave. The first PM is configured to modulate the first split light wave in response to a first multi-level electrical signal to produce a first modulated light wave. The second PM is configured to modulate the second split light wave in response to a second multi-level electrical signal to produce a second modulated light wave. The OC is then configured to combine the first modulated light wave and the second modulated light wave to generate a QAM optical signal.

Abstract: In some embodiments, an apparatus includes a memory and a processor operatively coupled to the memory. The processor is configured to be operatively coupled to a first optical transponder and a second optical transponder. The processor is configured to receive, from the second optical transponder, a signal representing a skew value of an optical signal and a signal representing a bit-error-rate (BER) value of the optical signal. The skew value is associated with a skew between an in-phase component of the optical signal and a quadrature component of the optical signal. The processor is configured to determine, based on at least one of the skew value or the BER value, if a performance degradation of the first optical transponder satisfies a threshold. The processor is configured to send a control signal to the first optical transponder to adjust a pulse shaping or a data baud rate of the first optical transponder.

Abstract: In some embodiments, an apparatus includes a memory and a processor operatively coupled to the memory. The processor is configured to send a stimulus signal at a frequency that corresponds to a first frequency value to a tributary channel of a coherent optical transponder. The processor is configured to adjust an amplitude of the stimulus signal and receive a first plurality of output optical power values. The processor is configured to adjust the frequency of the stimulus signal and receive a second plurality of output optical power values. The processor is configured to determine a bandwidth limitation and a modulation nonlinearity, and then send a first signal to a first filter to reduce the bandwidth limitation and a second signal to a second filter to reduce the modulation nonlinearity.

Abstract: The present disclosure provides a light receiving stacked-hole structure and a fabrication method thereof, and a fingerprint recognition device. The method includes forming a base light blocking layer having a first opening on a first surface of a substrate; forming at least one overlying light blocking layer having a second opening on a side of the base light blocking layer away from the substrate, wherein the overlying light blocking layer having the second opening is formed by using the base light blocking layer as a mask plate.

Abstract: In some embodiments, an apparatus includes a memory and a processor operatively coupled to the memory. The processor is configured to send a stimulus signal at a frequency that corresponds to a first frequency value to a tributary channel of a coherent optical transponder. The processor is configured to adjust an amplitude of the stimulus signal and receive a first plurality of output optical power values. The processor is configured to adjust the frequency of the stimulus signal and receive a second plurality of output optical power values. The processor is configured to determine a bandwidth limitation and a modulation nonlinearity, and then send a first signal to a first filter to reduce the bandwidth limitation and a second signal to a second filter to reduce the modulation nonlinearity.

Abstract: Disclosed in the present invention are a salt type and crystal type of 4H-pyrazolo[1, 5-alpha]benzimidazole compound and the preparation method and intermediate thereof.

Abstract: In some embodiments, an apparatus includes a memory and a processor operatively coupled to the memory. The processor is configured to be operatively coupled to a first optical transponder and a second optical transponder. The processor is configured to receive, from the second optical transponder, a signal representing a skew value of an optical signal and a signal representing a bit-error-rate (BER) value of the optical signal. The skew value is associated with a skew between an in-phase component of the optical signal and a quadrature component of the optical signal. The processor is configured to determine, based on at least one of the skew value or the BER value, if a performance degradation of the first optical transponder satisfies a threshold. The processor is configured to send a control signal to the first optical transponder to adjust a pulse shaping or a data baud rate of the first optical transponder.

Abstract: In some embodiments, an apparatus includes a quadrature amplitude modulation (QAM) optical modulator which includes a first phase modulator (PM), a second PM, a tunable optical coupler (TOC), and an optical combiner (OC). The TOC is configured to split a light wave at an adjustable power splitting ratio to produce a first split light wave and a second split light wave. The first PM is configured to modulate the first split light wave in response to a first multi-level electrical signal to produce a first modulated light wave. The second PM is configured to modulate the second split light wave in response to a second multi-level electrical signal to produce a second modulated light wave. The OC is then configured to combine the first modulated light wave and the second modulated light wave to generate a QAM optical signal.

Abstract: Disclosed in the present invention are a salt type and crystal type of 4H-pyrazolo[1,5-alpha]benzimidazole compound and a preparation method and intermediate thereof.

Abstract: An apparatus includes a finite impulse response (FIR) filter to receive a digital signal and a transmitter, operatively coupled to the FIR filter, to transmit an analog signal, converted from the digital signal, to a communication channel. The FIR filer is configured to change at least one operating parameter based on a bandwidth of the analog signal after transmission in the communication channel. The bandwidth of the analog signal is estimated, using an estimator, based at least in part on raw sampling data generated by an analog-to-digital converter (ADC) operatively coupled to the transmitter.

Abstract: In some embodiments, an apparatus includes an optical transceiver having a photo diode and a processor configured to be operatively coupled to the photo diode. The photo diode is configured to measure a set of receiver optical power (ROP) values at a set of baud rate values. The processor is configured to measure a set of bit error rate (BER) values of a digital modulated signal at the set of baud rate values. The processor is configured to determine an estimated optical signal noise ratio (OSNR) value at a baud rate value from the set of baud rate values based on the set of ROP values and the set of BER values. The processor is configured to send a signal indicating the estimated OSNR value at the baud rate value such that a planned route is selected to send data signals based on the estimated OSNR value.

Abstract: In some embodiments, an apparatus includes a quadrature amplitude modulation (QAM) optical modulator which includes a first phase modulator (PM), a second PM, a tunable optical coupler (TOC), and an optical combiner (OC). The TOC is configured to split a light wave at an adjustable power splitting ratio to produce a first split light wave and a second split light wave. The first PM is configured to modulate the first split light wave in response to a first multi-level electrical signal to produce a first modulated light wave. The second PM is configured to modulate the second split light wave in response to a second multi-level electrical signal to produce a second modulated light wave. The OC is then configured to combine the first modulated light wave and the second modulated light wave to generate a QAM optical signal.

Abstract: In some embodiments, a non-transitory processor-readable medium storing code representing instructions to be executed by a processor comprises code to cause the processor to determine, during a calibration of a coherent optical transmitter, a set of parameters associated with each tributary channel by sending a first signal to a digital signal processor (DSP) to adjust a scale factor of that tributary channel. The scale factor is associated with a tap characteristic of a finite impulse response (FIR) filter of the DSP. The code further causes the processor to determine a power imbalance between two tributary channels based on the set of parameters associated with each tributary channel. The code further causes the processor to send a second signal to the coherent optical transmitter to adjust a set of operational settings of the coherent optical transmitter based on the power imbalance and the set of parameters associated with each tributary channel.

Abstract: The present invention provides a pyrimidine derivative and a use thereof. The pyrimidine derivative is the compound shown in formula I or a pharmaceutically acceptable salt, hydrate, solvate, metabolite or prodrug thereof, wherein, R1, R2, R3, R4 and R5 are, for example, as defined in the specification. The compound can act as an ALK inhibitor, and is for preparing an anti-tumor medicament for suppressing an anaplastic lymphoma kinase.

Abstract: Disclosed in the present invention are a salt type and crystal type of 4H-pyrazolo[1, 5-alpha]benzimidazole compound and the preparation method and intermediate thereof.

Abstract: An apparatus includes a finite impulse response (FIR) filter to receive a digital signal and a transmitter, operatively coupled to the FIR filter, to transmit an analog signal, converted from the digital signal, to a communication channel. The FIR filer is configured to change at least one operating parameter based on a bandwidth of the analog signal after transmission in the communication channel. The bandwidth of the analog signal is estimated, using an estimator, based at least in part on raw sampling data generated by an analog-to-digital converter (ADC) operatively coupled to the transmitter.

Abstract: In some embodiments, a non-transitory processor-readable medium storing code representing instructions to be executed by a processor comprises code to cause the processor to determine, during a calibration of a coherent optical transmitter, a set of parameters associated with each tributary channel by sending a first signal to a digital signal processor (DSP) to adjust a scale factor of that tributary channel. The scale factor is associated with a tap characteristic of a finite impulse response (FIR) filter of the DSP. The code further causes the processor to determine a power imbalance between two tributary channels based on the set of parameters associated with each tributary channel. The code further causes the processor to send a second signal to the coherent optical transmitter to adjust a set of operational settings of the coherent optical transmitter based on the power imbalance and the set of parameters associated with each tributary channel.

Abstract: Techniques are described for determining, with a first optical node, a correction factor indicative of an amount of optical power loss that a Raman amplifier in a second optical node causes in an optical signal having a first wavelength that is transmitted by the first optical node and received by the second optical node, transmitting, with the first optical node to the second optical node, information, based on the determined correction factor, that is to be used for determining a gain of the Raman amplifier, and transmitting, with the first optical node to the second optical node, an optical signal having a second wavelength that is to be amplified by the Raman amplifier.

Abstract: An optical device may include a transmitter to provide an optical signal via a set of channels and a modulator. The optical device may include two or more tributary modulators to modulate the set of channels with a training pattern. The optical device may include a set of optics to alter a first channel relative to a second channel of the set of channels. The optical device may include a detector to determine an optical power measurement of the optical signal after the first channel is altered relative to the second channel. The optical device may include a controller to generate a control signal to adjust a power balance associated with the optical signal based on the optical power measurement. The optical device may include a controller to provide the control signal to a tributary modulator to alter a modulation of the optical signal.

Abstract: Techniques are described for characterizing a receiver front end of a pluggable optical module. The pluggable optical module receives an optical signal that includes a first portion having a first polarization and a second portion having a second polarization. The first portion and second portion are not coherent with one another and the power of the first portion and second portion is equal.