Abstract: A transmitter and receiver integrated optical sub-assembly includes a housing including a side wall structure and a bottom wall, a transmitter-side optical receptacle and a receiver-side optical receptacle attached to the side wall structure, a second circuit board inserted into the housing, laser diodes and photo diodes arranged on the bottom wall, a transmitter-side optical system that is disposed on the bottom wall and combines optical signals from the laser diodes, a receiver-side optical system that is disposed on the bottom wall and splits an optical signal from the receiver-side optical receptacle, a driver integrated circuit, and an amplifying integrated circuit. In the transmitter and receiver integrated optical sub-assembly, electrodes formed at the other end portion of the second circuit board are connected to the driver integrated circuit and the amplifying integrated circuit.

Abstract: An optical module includes a first circuit board, an optical sub-assembly, a first flexible printed circuit and a second flexible printed circuit. At first electrical connection terminals and a first electrical connector are provided on the first circuit board. The optical sub-assembly includes a second circuit board that includes second electrical connection terminals and a second electrical connector. The first flexible printed circuit is connected to the first electrical connection terminals and the second electrical connection terminals. The second flexible printed circuit is connected to the first and second electrical connectors. A high-speed electrical signal of 1 GHz or higher is transmitted between both the circuit boards through the first flexible printed circuit, and a power source signal and a low-speed electrical signal of 1 MHz or lower are transmitted between both the circuit boards through the second flexible printed circuit.

Abstract: A transmitter and receiver integrated optical sub-assembly includes a housing including a side wall structure and a bottom wall, a transmitter-side optical receptacle and a receiver-side optical receptacle attached to the side wall structure, a second circuit board inserted into the housing, laser diodes and photo diodes arranged on the bottom wall, a transmitter-side optical system that is disposed on the bottom wall and combines optical signals from the laser diodes, a receiver-side optical system that is disposed on the bottom wall and splits an optical signal from the receiver-side optical receptacle, a driver integrated circuit, and an amplifying integrated circuit. In the transmitter and receiver integrated optical sub-assembly, electrodes formed at the other end portion of the second circuit board are connected to the driver integrated circuit and the amplifying integrated circuit.

Abstract: An optical module includes a first circuit board, an optical sub-assembly, a first flexible printed circuit and a second flexible printed circuit. At first electrical connection terminals and a first electrical connector are provided on the first circuit board. The optical sub-assembly includes a second circuit board that includes second electrical connection terminals and a second electrical connector. The first flexible printed circuit is connected to the first electrical connection terminals and the second electrical connection terminals. The second flexible printed circuit is connected to the first and second electrical connectors. A high-speed electrical signal of 1 GHz or higher is transmitted between both the circuit boards through the first flexible printed circuit, and a power source signal and a low-speed electrical signal of 1 MHz or lower are transmitted between both the circuit boards through the second flexible printed circuit.

Abstract: A light-receiving circuit includes an optical-to-electrical transduction element, a TIA processing section to output a voltage in proportion to a current input from the optical-to-electrical transduction element, and a control section to control the TIA processing section. The TIA processing section includes a TIA, which generates the voltage output signal in proportion to the current input from the optical-to-electrical transduction element, an amplifier, which amplifies the output signal of the TIA, a monitoring portion, which monitors the current to be input to the TIA, and an offset-adjusting portion provided between the TIA and the amplifier to adjust and output an offset level of the output signal of the TIA to the amplifier. The control section acquires a value of the current to be input from the monitoring portion to the TIA, and controls the offset-adjusting portion so as to adjust the offset level in proportion to that acquired current value.

Abstract: A light-receiving circuit includes an optical-to-electrical transduction element, a TIA processing section to output a voltage in proportion to a current input from the optical-to-electrical transduction element, and a control section to control the TIA processing section. The TIA processing section includes a TIA, which generates the voltage output signal in proportion to the current input from the optical-to-electrical transduction element, an amplifier, which amplifies the output signal of the TIA, a monitoring portion, which monitors the current to be input to the TIA, and an offset-adjusting portion provided between the TIA and the amplifier to adjust and output an offset level of the output signal of the TIA to the amplifier. The control section acquires a value of the current to be input from the monitoring portion to the TIA, and controls the offset-adjusting portion so as to adjust the offset level in proportion to that acquired current value.

Abstract: An optical module includes a housing, an optical adapter attached to an end portion of the housing, and an optical transmitter and receiver assembly mounted in the housing. The optical transmitter and receiver assembly includes a TOSA including a plurality of light-emitting elements, a ROSA including a light-receiving element, and a circuit board electrically connected to the TOSA and the ROSA. The TOSA further includes a TOSA base having an opposing side surface on which the plurality of light-emitting elements are oppositely arranged so as to form at least one pair. The circuit board includes a first flexible substrate mounting the TOSA and a first rigid substrate connected to the first flexible substrate. The first flexible substrate includes a TOSA base facing-portion facing the TOSA base, and a connection portion extending from both end portions of the TOSA base-facing portion and connected to the plurality of light-emitting elements.

Abstract: A laser driver IC has an RS flip-flop for latching a signal that indicates an event of fault detection, to output it as an internal fault signal, and a fault signal processing section for generating a disable signal for inactivating the driving function of the laser driver IC in response to output of the RS flip-flop. One of outputs of the fault signal processing section is connected to a fault signal output terminal linked to outside the laser driver IC.

Abstract: A laser driver IC has an RS flip-flop for latching a signal that indicates an event of fault detection, to output it as an internal fault signal, and a fault signal processing section for generating a disable signal for inactivating the driving function of the laser driver IC in response to output of the RS flip-flop. One of outputs of the fault signal processing section is connected to a fault signal output terminal linked to outside the laser driver IC.