Opnext Japan, Inc.

Other

Oclaro Japan, Inc.

Tomonao Kikuchi

Yasuhiro Yamada

Akihiro Hayami

Shigeru Tokita

Naohiko Baba

Hiroo Matsue

Tadashi Hatano

Takayuki Nakao

Toshiaki Murai

Tomoaki Shimotsu

Masayuki Miyoshi

Hidehiro Ikeuchi

Antony Cleitus

Tohru Oyama

Tadaaki Fujii

Hiroshi Yamamoto

Mitsuo Akashi

Hiroki Irie

To provide an optical module and a method for aligning the optical module with which alignment can be easily performed. An optical module includes first optical element sections and a second optical element section optically joined to the first optical element sections. Each first optical element section includes an optical conversion element, a ferrule having a distal end being in contact with and optically joined to the second optical element section, and a first optical system disposed in a position where the ferrule and the optical conversion element are optically adjusted. The second optical element section includes joining sections in contact with and joined to, in joining parts, the distal ends of the ferrules, a wavelength multiplexing optical element optically joined to the optical conversion elements, and second optical systems respectively disposed in positions where the wavelength multiplexing optical elements and the joining parts are optically adjusted.

Optical module and method for aligning optical module

A master station includes a group of circuits for performing an optimization method. In such a system, the optimization is achieved by adjusting the pull-up resistance and by setting the best possible clock frequency to ensure that data/clock high and low voltage levels are within predetermined specifications. An optimization procedure is performed in a calibration phase invoked by a user or a system whenever a change is introduced to the system, such as addition or deletion of slave stations, a change of data/clock lines, or a change that may affect on the electrical and timing characteristics of the two-wire communication system.

Bidirectional communication system and calibrator

A reader/writer is provided which is capable of speedily recognizing a correspondence between one end and the other end of a fiber-optic cable when a plurality of fiber-optic cables is laid. The reader/writer according to the present invention reads, on receiving through the fiber-optic cable a signal that is an instruction to read data from a RF tag mounted to an end of the fiber-optic cable, data from the RF tag through radio communication, and transmits the read data through the fiber-optic cable. Also, on receiving through the fiber-optic cable a signal that is an instruction to write data into the RF tag and a signal indicating the write data, the reader/writer writes the write instruction and the write data into the RF tag through radio communication.

Reader/writer, optical transceiver module, and cable system

A temperature compensating circuit includes a first circuit network between an inverting input terminal of an operational amplifier and an output terminal of the operational amplifier , and a second circuit network between the inverting input terminal of the operational amplifier and a reference potential. At least one of the first circuit network and the second circuit network is made of an arrangement containing a plurality of series-connected thermistor/resistor pairs in which the thermistors are connected parallel to the resistors, and the temperature compensating circuit compensates a temperature-dependent signal which is inputted into a positive phase input terminal of the operational amplifier , and outputs the temperature-compensated signal.

Temperature compensating circuit, temperature compensating logarithm conversion circuit and light receiver

Two sets of a high speed differential amplifier and a low speed differential amplifier are prepared, and frequency response speeds of these high speed/low speed differential amplifiers are different from each other. Both an oscillating frequency and a frequency modulation sensitivity of a ring oscillator type voltage-controlled oscillator circuit can be separately set by adding two outputs of these differential amplifiers to each other and by varying the selection ratio of these high speed/low speed differential amplifiers in a linear manner. Thus, the setting ranges for the oscillating frequency and the frequency modulation sensitivity are enlarged. At this time, since a summation of currents flowing through the high speed/low speed differential amplifiers is continuously made constant, the oscillating frequency depending characteristic of the output amplitude of the VCO circuit can be canceled. Furthermore, since control signals are supplied in a differential structure, increasing of jitter components caused by the common mode noise can be suppressed.

Optical receiver module optical transmitter module phase-locked loop circuit voltage-controlled oscillator and frequency response controllable amplifier

Growing community of inventors

Fujisawa, Japan

Tomonao Kikuchi