Abstract: An optical isolator capable of creating a larger safe buffer area for optical beam(s) and a manufacturing method thereof are disclosed. The optical isolator includes a sandwich type wafer, a first polarizer, a Faraday rotator and a second polarizer. The first polarizer works as the incident plane of the FSI (free space isolator), while the second polarizer works as the outgoing plane of the FSI. The direction in which the second polarizer passes the polarized beam is at a 45° angle with respect to the first polarizer. The manufacturing method includes marking the edge of the second polarizer. FSIs processed by this method provide a larger buffer area for the optical beam(s) and/or a lower manufacturing cost, even though the size of the FSI is unchanged.

Abstract: Methods and circuits for providing a minimum driving voltage to a current-driven load (such as a laser diode) are disclosed. The circuit and methods may be useful for efficiently providing a bias and/or driving current to the current-driven load with minimal energy loss. The circuit generally comprises (1) a driver or voltage source configured to provide the bias and/or driving current to the current-driven load, (2) a sense circuit configured to (i) sense the bias and/or driving current and (ii) convert the bias and/or driving current to a first voltage, and (3) a comparator configured to (i) receive the first voltage and first and second reference voltages and (ii) provide a feedback/error signal to the driver or voltage source, the feedback/error signal configured to maintain or adjust the bias and/or driving current at or towards a target value.

Abstract: Methods, algorithms, architectures, circuits, and/or systems for determining the status of parameters associated with optical transceiver operation are disclosed. The method can include (a) accessing and/or monitoring parametric data for each of a plurality of parameters that are related to operation of the optical transceiver; (b) storing the parametric data in one or more memories; (c) comparing the parametric data for each of the plurality of parameters against at least one of a corresponding plurality of predetermined thresholds; and (d) generating one or more states indicating whether the parametric data for a unique one of the parameters has crossed one or more of the corresponding plurality of predetermined thresholds. The invention also relates to an optical triplexer, comprising the described optical transceiver.

Abstract: Methods for receiving a signal and a detection circuit are disclosed. The detection circuit and related methods may be useful for the fast and accurate receiving of data signals. The detection circuit generally comprises a first circuit having a first time constant, a second circuit having (i) a common input with the first circuit and (ii) a second time constant, the second time constant being less than the first time constant, and a switch configured to (i) charge the first circuit with an input signal when the switch is in a first state, and (ii) charge or discharge the second circuit with the input signal when the switch is in a second state, the switch having the second state when the input signal is no longer received at the common input.

Abstract: A light-emitting device, multi-channel light-emitting device, and method(s) of making the same are disclosed. The light-emitting device can include a substrate; a lower contact layer on or over the substrate comprising a first lower contact in a first region and a plurality of second lower contacts in a second region; a plurality of light-emitting thin film devices on or over the first lower contact in the first region; a plurality of light-modulating thin film devices on or over the plurality of second lower contacts in the second region; a plurality of first upper contacts on or over the plurality of light-emitting thin film devices; a plurality of second upper contacts on or over the plurality of light-modulating thin film devices; and an isolation region between the first and second regions, electrically separating the plurality of first upper contacts and the plurality of second upper contacts.

Abstract: An optical transceiver having an integrated optical time domain reflectometer monitoring unit and methods for using the same are disclosed. The disclosure relates to an optical transceiver comprising an optical device comprising a wavelength division multiplexing system (WDM), a data signal driver, a data signal limiting amplifier, and an optical time domain reflectometer (OTDR) data processing module. Furthermore, the optical transceiver is particularly advantageous in an optical line terminal (OLT) and/or a passive optical network (PON). The integrated OTDR data processing module can protect the optical transceiver, ensure successful monitoring data, simplify network wiring and decrease system and network costs by decreasing the number of OTDR modules and WDM units.

Abstract: A small form-factor pluggable (SFP) optical transceiver includes a casing configured to accommodate optical and electrical devices. During normal operation, the casing is connected to a switchboard via a connector in the switchboard, and the optical devices are outside the switchboard, thereby exposing optical devices sensitive to high temperature to the outside air, reducing the operational temperature of the optical device portion relative to the heated portion inside the switchboard. Thus, the present SFP optical transceiver advantageously improves operational performance and extends the life of the device. Also, the present SFP optical transceiver having the optical device portion outside the switchboard advantageously improves the cooling performance for the optical device portion.

Abstract: An optical triplexer and/or optical line terminal (OLT) compatible with 1.25 and 10 Gb/s passive optical networks is disclosed. The triplexer/OLT includes an optical fiber, first and second laser diodes, a photodiode, and first and second lenses. A hemispherical lens may be at an end face of the photodiode or receiver subassembly housing. A first optical splitter is mounted between the first and second lenses, and a second optical splitter is mounted between the optical fiber and the second laser diode. The first lens and first laser diode, and the second lens and second laser diode share respective common linear optical axes. The present triplexer/OLT advantageously accords with an interface standard IEEE802.3av-2009 PRX30. In addition, the present triplexer can advantageously implement analog receiving and digital transceiving, save optical fiber resources, and provide high efficiency coupling. Thus, requirements for high power output and smaller housing outlines can be served.

Abstract: Methods, architectures, circuits, and/or systems for monitoring operating parameters and/or generating status indications associated with electronic device operation are disclosed. The method can include (i) monitoring a first operating parameter related to operation of the electronic device to determine a first parameter value, (ii) calculating a difference between the first parameter value and a predetermined value for the first operating parameter, (iii) monitoring a second operating parameter on which thresholds for operational warnings and/or alarms are based to determine a second parameter value, (iv) updating or changing the thresholds based on a predetermined change or event in the second parameter value, (v) comparing the difference to the updated or changed thresholds, and (vi) generating a corresponding one of the operational warnings and/or alarms when the difference crosses at least one of the thresholds in a predetermined direction.

Abstract: The present disclosure relates to a differential drive circuit. The differential drive circuit generally includes a differential driver, a first transmission line coupled to a first output node of the differential driver, and a second transmission line coupled to a second output node of the differential driver. A laser diode is coupled to the first and second transmission lines. The first and second transmission lines have different delays, lengths, or impedances. In some embodiments, the delay between the first transmission line and the second transmission line is 0.2-0.4 times a rise time or fall time of a signal on either transmission line.

Abstract: The present disclosure relates to an optical transceiver for use in optical fiber communications and/or telecommunications systems and, more specifically, a low power consumption, long range pluggable transceiver. The transceiver generally comprises a photodiode with a transimpedance amplifier (PIN-TIA); an electro-absorption modulated laser (EML); an optical detector; and a directly modulated laser (DML) driving module connected between the PIN-TIA and EML laser configured to drive the EML laser. A low power-consumption DML driving module is utilized to drive the EML laser, so as to further reduce power consumption. An impedance matching circuit can be applied to modulate an electro-absorption (EA) modulator of the EML laser with maximum efficiency.

Abstract: An optical transceiver and/or optical network, and methods of monitoring optical transceivers, may be useful for increasing the dynamic range and/or determining the received signal strength and/or link budget of the optical transceiver and/or a different optical transceiver in the optical network. The circuitry generally comprises a photodiode configured to generate a first current responsive to an optical signal, a current mirror configured to produce a second current equal or proportional to the first current, and a nonlinear element configured to produce a first voltage from the first current.

Abstract: Methods for detecting and/or indicating the presence of valid data and threshold setting and data detection circuitry are disclosed. The threshold setting and data detection circuitry and related methods may be useful for fast and accurate reception of optical signals. The detection circuit generally comprises (i) a first circuit configured to regulate or control a DC offset of a differential input signal, and (ii) a second circuit coupled to the first circuit, the second circuit configured to indicate the presence of a data signal at the differential input signal when a voltage difference between true and complementary nodes of the differential input signal is above a predetermined threshold.

Abstract: An optical transceiver and methods for using the same are disclosed. The optical transceiver and methods may be useful for providing more accurate information regarding trends in operation of the optical transceiver, predicting an impending failure of the optical transceiver, and providing details of the optical transceiver prior to failure. The optical transceiver generally includes (1) at least one of (i) a receiver configured to receive optical information and (ii) a transmitter configured to transmit optical information, (2) circuitry configured to sample data for one or more operational parameters of the receiver and/or transmitter, (3) logic configured to perform one or more statistical calculations on the sampled data to generate statistical information, and (iv) one or more memories configured to store the sampled data and the statistical information.

Abstract: A circuit, optical transceiver and/or methods for using the same may be useful for determining average power, extinction ratio, and/or modulation amplitude when monitoring an optical transceiver and/or optical network. The circuit generally comprises a photodiode configured to generate a first current responsive to an optical signal, a current mirror coupled to a first terminal of the photodiode, and a detector coupled to a second terminal of the photodiode. The current mirror is configured to produce a second current equal to or proportional to the first current, and the detector is configured to determine a power or amplitude of the optical signal. Further, the present scheme may communicate information using a low speed signal superimposed on or combined with the relatively high speed optical signal.

Abstract: An alignment system includes a stage configured to retain an object, an image-capturing device configured to capture the image of the field of view of the microscope, and a processing module configured to generate a virtual mask and superimpose the virtual mask with the image of the object. In one embodiment of the present invention, a method for operating a virtual mask system includes the steps of generating a virtual mask, placing a first object on a stage, capturing at least one image of the first object, and superimposing the virtual mask with the image of the first object by adjusting a position or an inclined angle of the stage or adjusting a capturing position of an image-capturing device by considering at least the virtual mask and the image of the first object.

Abstract: Methods, algorithms, architectures, circuits, and/or systems for determining the status of parameters associated with optical transceiver operation are disclosed. The optical transceiver can include an optical receiver to receive optical data; an optical transmitter to transmit optical data; one or more memories to store data (and, optionally, thresholds) for each of a plurality of parameters that are related to operation of at least one of the optical receiver and the optical transmitter; a microprocessor that compares the parametric data against the threshold(s) to calculate one or more flags to indicate whether a corresponding parameter has exceeded the first or second threshold; and an interface that receives a flag request from a host, and provides the one or more flags in response to the request. In the present disclosure, the microprocessor may calculate the one or more flags only in response to the flag request from the host.

Abstract: Methods, algorithms, architectures, circuits, and/or systems for dynamically allocating memory for storing parametric data in optical transceivers are disclosed. The optical transceiver can include an optical receiver configured to receive optical data; an optical transmitter configured to transmit optical data; a microprocessor configured to access data for each of a plurality of parameters that are related to operation of at least one of the optical receiver and the optical transmitter; one or more memories configured to store the data at a plurality of locations that are dynamically allocated by the microprocessor; and an interface configured to receive a request for data for one or more of the parameters from a host and provide the data in response to the request. In the present disclosure, the host is unaware of the locations at which the parametric data are stored.

Abstract: A circuit for monitoring an optical receiver or transceiver, architectures, circuits, and systems including the same, and a method for monitoring received optical power are disclosed. The receiver monitoring circuit comprises an avalanche photodiode (APD), a microprocessor, and first and second transresistance amplifiers. The microprocessor is configured to supply bias voltage to the APD. Photocurrent produced by the APD is supplied to the first and second transresistance amplifiers, and then the microprocessor captures optical power from the voltage signal of the first and second transresistance amplifiers.

Abstract: The present disclosure relates to an optical power monitoring circuit including an automatic power control (APC) loop and a microcontroller unit (MCU), and a method for monitoring the same. The APC loop comprises a laser diode (LD) and a feedback loop to maintain a laser optical power. The MCU is configured to (i) monitor a bias current using a current sense circuit, (ii) monitor a rate of change of the bias current with time, and (iii) adjust a target power of the APC loop. By monitoring the bias current and the rate of change, and comparing them against thresholds, the target power can be adjusted by the MCU, to prevent roll-over in the laser diode, damage to the laser, and/or a hard failure in the data links that use the laser.