Finisar Corporation

Ruizhang Technology Limited Company

Steve Wang

Johnny Zhong

Frank H Levinson

Yin Zhang

William R Freeman

Ping Peter Xie

Yonglin Huang

William Schnaitter

Kevin Dapeng Zhang

Liren Du

Qi Deng

Ming Kun Shi

Jian S Liu

Xuejun Lu

James Finn Aldridge

Mingkun Shi

Senlu Xu

Tengda Du

Chang-Chi Liu

Robert Huang

Chee Kwang Quek

David Pin

Lewis Leung

Xin Lou

Johhny Zhong

Methods, apparatuses, and system for performing at least one of error correction or error detection are described. In one embodiment, a radio frequency identification (RFID) tag receives a signal activating or interrogating the tag. The tag includes memory that stores data associated with the tag. The tag performs at least one of error detection or error correction on the stored data. The error detection includes detecting, by the tag, that one or more bits of the stored data are inflicted with an error. The error correction includes correcting the erroneous bit if the error affects less than a predetermined number of the bits of the stored data. The tag transmits the stored data to a reader in response to the detection or correction. The reader can analyze the stored data for additional information about the error or provide the stored data to another computing system that performs the analysis.

Selective application of error detection and correction for radio frequency identification

A Power-on Reset circuit is described. The Power-on Reset is formed by two comparators and a latch circuit. The Power-on Reset circuit will de-assert the reset state once the supply voltage reaches a first reference point and re-assert the reset state once the supply voltage drops below a second reference point. The Power-on Reset circuit disclosed further includes circuits to initialize properly and to ensure the regulator voltage and the bandgap voltages are stable and above the ground level voltage.

Power-on reset circuit

Disclosed is a fractional bandgap circuit and method to provide a same reference voltage value in a variety of circumstances of operation, including variations in manufacturing process, temperature, and a supply voltage. The disclosed fractional bandgap circuit and method also allows for low supply voltage operation within a compact layout area.

Fractional bandgap circuit with low supply voltage and low current

An input power on a tag is monitored. An input impedance of the tag is adjusted based on the monitored input power to increase a backscatter level of the tag. In one embodiment, an output voltage of a rectifier device is monitored. An input power to the tag is determined based on the output voltage. An input impedance of the tag is adjusted based on the input power to increase the backscatter level of the tag.

Increasing backscatter level for RFID chip

An optical transceiver device including a modulating assembly. In contrast with conventional transceivers, the optical transceiver device uses a modulating assembly rather than a laser. The modulating assembly is located within the transceiver itself and includes first and second collimating lenses, first and second mirrors, and a p-i-n diode. An optical signal that has not yet been modulated is introduced into the modulating assembly via the first collimating lens, and is redirected toward the p-i-n diode via the first mirror. Depending on the voltage state of the diode, the light signal is either transmitted through the diode or prevented from passing, which results in modulation of the signal for data transmission. The modulated signal passes through the modulating assembly and is reflected by the second mirror toward the second collimating lens, through which it passes before exiting the transceiver.

Optical transceiver having a modulating component

A WDM add/drop module. The drop portion of the add/drop module is accomplished by using thin film filters or thin film interleavers. The add portion of the add/drop module uses fused fiber interleavers for the less critical stages of the multiplexing process. In a final stage, fused fiber interleavers can be placed in series. A thin film intervleaver having a flattop frequency response may also be used for the critical stage where the multiplexed channels are more closely spaced. The frequency response of the thin film interleaver is relatively constant across a bandwith of a channel while having a drop off at the channel edge to reduce cross talk.

Optical add/drop module

Systems and methods provide for the addition of DWDM modules to CWDM systems in order to increase bandwidth over existing lines. This allows for the expansion of communications capacity without the need to replace existing CWDM systems. The DWDM modules can be transparently inserted into the CWDM systems by, in the CWDM system, reserving a channels for use by the DWDM. The DWDM system then occupies that channel with a scalable number of DWDM wavelength channels, for example four, eight, or sixteen. The DWDM systems can be used in both single and dual fiber systems as well as ring systems. Use of single fiber systems is obtained by implementing coupling devices, such as interleavers, passband filters, and circulators, that can used in pairs to couple bidirectional signals over a single fiber.

Scalable and movable DWDM usage of CWDM networks

Methods and structures for reducing and/or eliminating moisture penetration in an optical package. The optical package may include (1) a layer of inorganic material placed over the points of the optical package susceptible moisture penetration of the optical package; (2) a portion of hygroscopic material placed over the points of the optical package susceptible to moisture penetration; (3) a layer of hygroscopic material placed on the interior surface of the optical package; and/or (4) a layer of hydrophobic material coated on the optical surfaces of the optical package.

Surface passivation and sealing of micro-optics devices for improved performance in harsh environments

A thin film interleaver device is disclosed. The thin film interleaver includes thin film optics. The thin film(s) are formed such that they reflect one group of wavelengths while allowing a second group of wavelengths to pass through the thin film(s). The thin film(s) exhibit a flat top frequency response across the channel bandwidths of the multiplexed signal for which the thin film filter is designed such that the thin film interleaver is less sensitive to wavelength drift and temperature variations.

Thin film interleaver

An optical waveguide for use in amplifying light signals with an integrated gain equalization filter. The optical waveguide includes a gain section for amplifying light signals. The optical waveguide further includes an equalization filter to improve the uniformity of optical gain over a wavelength range for which the gain section is intended to provide amplification.

Integration of a gain equalization filter in a gain medium

A compact optical isolator includes a polarizer, a Faraday rotator, and an analyzer that are arranged in series. A magnet is also included to provide a magnetic field to the Faraday rotator. The outer edges of the polarizer, Faraday rotator, and analyzer are preferably parallel to each other and to the optical path of the incoming light beam so that the optical aperture through the optical isolator is maximized. In addition, each of the polarizer, the Faraday rotator, and the analyzer have at least one facet in the optical path of the light beam that is tilted from perpendicular with respect to the light beam such that reflections are avoided. The analyzer may have a wedge shape such that one surface mates level with an optical fiber and the opposing surface is tilted to prevent reflections. Alternatively, a wedge-shaped block may be located between the analyzer and the optical fiber.

Connector mountable asymmetric free space optical isolators

Systems and methods use single-fiber optical add/drop multiplexers (OADMs) to enable bi-directional data transmission in WDM systems over a single fiber. By reducing the required capacity for an optical network from dual fibers to a single fiber, significant cost and bandwidth efficiencies are achieved. The systems and methods also provide redundancy protection in single-fiber bidirectional line ring systems. In the event of a downstream fiber or device failure, the OADM module receives a signal on a first wavelength from a first direction, shifts the signal from the first wavelength to a second wavelength, and sends the signal back down the fiber it originated from on the second wavelength, thus maintaining the propagation of the signal in the ring system.

Add/drop module for single fiber wavelength division multiplexing systems

A redundant optical signal transmission and reception system is disclosed to enable information exchange via an optical communications network without data loss in the event of optical transmitter or receiver failure. In one embodiment, the redundant optical signal system includes a primary transmission link comprising a plurality of optical transmitters and a multiplexor for modulating and combining electrical signals into a primary multiplexed optical signal. In the event of failure of an optical transmitter, a backup transmission link is activated to compensate for the malfunctioning transmitter. The backup transmission link utilizes a backup optical transmitter to modulate the electric signal formerly received by the malfunctioning optical transmitter. The backup transmission link combines the backup optical signal with the primary multiplexed optical signal to form a complete optical signal for transmission over the optical network. In another embodiment, a similar process is performed for providing backup optical signal reception.

System and method for preventing signal loss in an optical communications network

This disclosure is concerned with optical add/drop modules. In one example, he drop portion of the add/drop module is accomplished by using thin film filters or thin film interleavers. The add portion of the add/drop module uses fused fiber interleavers for the less critical stages of the multiplexing process. In a final stage, fused fiber interleavers can be placed in series. A thin film interleaver having a flattop frequency response may also be used for the critical stage where the multiplexed channels are more closely spaced. The frequency response of the thin film interleaver is relatively constant across a bandwidth of a channel while having a drop off at the channel edge to reduce cross talk.

Growing community of inventors

San Jose, CA, United States of America

Steve Wang