Sumitomo Electric Industries, Limited

Sumitomo Electric Device Innovations, Inc.

National Institute of Advanced Industrial Science and Technology

Kabushiki Kaisha Toshiba

Ntt Electronics Corporation

Moriyasu Ichino

Toshifumi Hosoya

Tadashi Sakai

Isao Karube

Shingo Kaimori

Takahiko Kitamura

Tomoko Ishikawa

Toru Ukai

Masao Gotoh

Hideaki Nakamura

Shigeo Hayashi

Satoshi Yoshikawa

Nobuyuki Matsumura

Mitsuaki Nishie

Yukio Sato

Hiroto Ishibashi

Kazuhiro Kuwa

Kenichiro Uchida

Tetsu Murayama

Toru Kawagishi

Junichi Kataoka

Seiichi Ishikura

Sigeo Hayashi

Yuanzhe Li

A method to control an optical transceiver, in particular, to drive an LD installed within the optical transceiver is described. The LD in the bias current thereof is determined by the automatic power control (APC) loop to keep an average of the optical output power. The modulation current is determined by a feedback loop to keep the extinction ratio (ER) in a preset range. The initial condition of the modulation current for the feedback loop is set by T-Im characteristic. The T-Im characteristic is first derived based on data measured in a status of the LD not installed in the transceiver. The T-Im characteristic is revised timely by the modulation current practically obtained for the optical transceiver.

Method to produce optical transceiver

A method to monitor an output of an APD is disclosed. The method includes steps of, (a) measuring dark currents of the APD at several temperatures in advance to a practical operation of the APD, (b) measuring an output current of the APD by illuminating the APD practically at a measured temperature, (c) estimating a dark current at the measured temperature from measured dark currents, and (d) subtracting the estimated dark current from the output current.

Method for measuring optical input power by avalanche photodiode

An algorithm to drive a semiconductor laser diode (LD) is disclosed. The algorithm assumes that the modulation current to keep the extinction ratio in constant has temperature dependence represented by an exponential function under the average output power of the LD is kept constant by an auto-power-control (APC). When a tracking error exists and the approximation by an exponential function is turned out in failure, the algorithm adds a correction to the exponential function determined by a difference between a practically measured modulation current and another modulation current calculated from a value determined for a bared LD.

Algorithm to drive semiconductor laser diode

A method to control an LD (laser diode) is disclosed. The method compares the operating temperature of the LD with a transition temperature. When the former temperature exceeds the latter, the modulation current is set based on the bias current, which is independently determined by the APC loop. On the other hand, the operating temperature is less than the transition temperature; the modulation current is determined by the operating temperature.

Method for driving optical transmitter

A biosensor measurement device for providing accurate measurement results within a short period of time by using only a very small amount of sample. The biosensor measurement device includes a power source, which is connected to a voltage regulator, a measurement instrument, and a controller for supplying power. When the biosensor chip is connected to the biosensor measurement device and a voltage is applied, the measurement instrument begins the measurement of a current value for the biosensor. When the measured current value or a measured charge value is greater than a reference value, the measurement is terminated in accordance with an instruction issued by the controller, and when the value is smaller than the reference value, the measurement is continued in accordance with a controller instruction.

Biosensor measurement machine, biosensor measurement system and biosensor measurement method

An optical receiver is disclosed, in which no additional photodiode to monitor the optical input level and no temperature control unit are necessary. The receiver of the invention provides an avalanche photodiode (APD) to receiver the first optical signal with the first wavelength and a PIN-PD to receive the second optical signal with the second wavelength. The optical input level for the APD is indirectly determined through the photocurrent generated by the PIN-PD and the bias voltage for the APD is so adjusted that the APD shows an optimum multiplication factor for the optical input level.

Optical receiver applicable to GPON system

A method to reduce a peak power consumption of an optical transceiver including a thermoelectric cooler (TEC) is disclosed. The transceiver includes three power units, one of which powers the temperature control unit including the TEC driver and the TEC, second one of which powers the transmitter unit including an LD and an LD driver, and the last of which powers the receiver unit. Once the transceiver is set in the host system, the transceiver first activates the first and second power units to start up the temperature control unit and the transmitter unit, and subsequently, the transceiver sets up the third power unit after the temperature of the LD is stabilized at a target temperature.

Optical transceiver with reduced peak power consumption and a method to reduce peak power consumption

An optical transmitter is disclosed in which the wavelength deviation occurred at the turning on from the disabled state to the enabled state by the negating of the Tx_Disable command is suppressed. The optical transmitter includes a semiconductor laser diode (LD) and an automatic temperature controller (ATC) circuit to drive the thermo-electric cooler (TEC). When the transmitter receives the Tx_Disable to start up the operation of the LD, a pulsed signal is generated in synchronizing with the transition of the Tx_Disable signal to momentarily enhance the cooling capacity of the TEC in order to compensate the increase of the temperature of the LD by the self heating, which prevents the output wavelength of the transmitter from deviating.

Optical transmitter suppressing wavelength deviation at beginning of operation

In a biosensor system and its measuring instrument which determine that a biosensor chip has been inserted and measure biological information on a biological material supplied to the biosensor chip, the size of the biosensor chip is made small, the reliability of the measuring instrument is improved, and the product life becomes long. In addition, a measurement error of the biological information is suppressed in measuring the biological information by inserting a biosensor chip, which has a sensor electrode formed of an electrode member with an electric resistance value higher than a conductive metal, into the measuring instrument.

Biosensor chip, biosensor system and measuring instrument thereof

An optical receiver of the present embodiment has a light-receiving block, a discriminating block, a detecting block, a controlling block, and an adjusting block. The light-receiving block generates complementary signals in accordance with a photo current output from a semiconductor light-receiving element which receives an optical signal. The discriminating block has a differential amplifier having input terminals connected to output terminals of the light-receiving block via respective coupling capacitors. The detecting block generates an intensity signal corresponding to the photo current. The controlling block generates a first signal in accordance with a dispersion signal corresponding to dispersion of an optical transmission line, a distance signal corresponding to the distance of the optical transmission line, and an intensity signal. The adjusting block generates a second signal used for adjusting an offset voltage between the inputs of the differential amplifier in accordance with the first signal, and an output terminal of the adjusting block is connected to one of the input terminals of the differential amplifier for providing the second signal.

Optical receiver

The present invention provides an optical transmitter that prevent the overshoot and undershoot appeared in the emission wavelength caused by the fluctuation of the temperature of the laser diode installed therein. The optical transmitter includes a TEC driver, and a master controller. The TEC driver, by comparing the monitored temperature with the target temperature, outputs the error signal to the master controller, which enables the LD-Driver only when the error signal continuously stays within a convergent range by a preset period.

Optical transmitter

The present invention is to prevent a snapping of wiring patterns formed on a flexible printed circuit (FPC) board by bending the FPC board and to make the length of the pattern short to suppress the degradation of high frequency signals transmitted on the wiring pattern. The FPC board provides a via hole in the land region formed on a primary surface of the FPC board and to be attached to the host board. The wiring pattern, which is formed on a secondary surface opposite to the primary surface and is made of copper foil, is drawn from the via hole at the secondary surface. The wiring pattern is covered by a cover layer. Bending the FPC board such that the primary surface is outside, the FPC board is bent at a boundary of the land region at the primary surface, while; the FPC board provides the cover layer on a region of the secondary surface corresponding to the land region, which prevents the wiring pattern on the second region from snapping.

Optical module with a flexible printed circuit board to be electrically connected with a host board

The invention discloses an optical receiver that prevents the instability of the bias voltage to the avalanche photodiode (APD) and facilitates the recovery of the bias voltage from the safety value. The optical receiver comprises the APD, the DC-DC converter to supply the bias voltage to the APD, the current detector to detect the photo current generated by the APD, and the controller to set the bias voltage. The controller, evaluating the optical input power based on the output voltage of the DC-DC converter and the monitored current, sets the output voltage based on the change of the optical input power.

Method for controlling a bias voltage applied to an avalanche photodiode

The present invention provides a method to maintain a multiplication factor of an avalanche photodiode independent on temperatures without additional devices. The light-receiving apparatus of the invention includes an avalanche photodiode (APD), a dividing circuit, and a bias supplying circuit. The APD has a first region, where a significant multiplication factor appears, and a second region without any multiplication factor. The dividing circuit extracts a second signal.

Light receiving method of an avalanche photodiode and a bias control circuit of the same

The present invention is to provide a light-receiving circuit, in particular, the circuit for an avalanche photodiode (APD), in which the current of the APD is dynamically controlled to protect the APD from the over current. The circuit comprises the high voltage source, the current mirror circuit connected to the high voltage source, the APD connected to one of the current output terminal of the current mirror circuit, and the current source connected to the other current output terminal of the current mirror circuit. The current flowing out from the other current output terminal is dynamically controlled by the current source to protect the APD from the over current.

Growing community of inventors

Yokohama, Japan

Moriyasu Ichino