Optical transceiver outputting wavelength multiplexed signal and receiving another wavelength multiplexed signal

Patent metadata

Field	Value
Publication number	US-2016149643-A1
Application number	US-201514940891-A
Country	US
Kind code	A1
Filing date	Nov 13, 2015
Priority date	Nov 20, 2014
Publication date	May 26, 2016
Grant date	—

Abstract

An optical transceiver that provides a receiver optical module including a plurality photodiodes (PDs) each biased through internal bias lines, signal lines carrying driving signals to an optical transmitter module, and external bias lines each connected to the internal bias lines. One of the internal bias lines connected to one of the external bias lines arranged closest to the signal lines has a length shorter than lengths of the other internal bias lines so as not to affect EMI noises induced from the signal lines to the other internal bias lines.

First claim

1 . An optical transceiver that transmits a wavelength multiplexed optical signal and receives another wavelength multiplexed optical signal, comprising:
an optical transmitter module configured to receive driving signals through signal lines, convert the driving signals into transmitting optical signals having respective wavelengths different from each other, and generate the wavelength multiplexed optical signal by multiplexing the transmitting optical signals depending on the wavelengths thereof; an optical receiver module configured to de-multiplex the other wavelength multiplexed signal into receiving optical signals, and convert the receiving optical signals into receiving signals by photodiodes (PDs); and a bias supply configured to supply biases to respective PDs through external bias lines including first external bias line and other external bias lines, the first external bias line being arranged closest to the signal lines carrying the driving signals to the optical transmitter module, wherein the optical receiver module provides internal bias lines including a first internal bias line connected to the first external bias line through a first terminal and other internal bias lines each connected to the external bias lines through terminals, the first internal bias line including a first filter unit having a resistor and a capacitor constituting an first RC filter, the other internal bias lines including other filter units each having a resistor and a capacitor constituting RC filters, and wherein the first internal bias line has a length from the first terminal to the resistor in the first filter unit shorter than lengths of the other internal bias lines from the respective terminals to the resistors in the other filter units.

2 . The optical transceiver of claim 1 ,
further including a wiring substrate, wherein the internal bias lines each include a first pattern formed on the wiring substrate and a bonding wire connecting the terminal to the first pattern, and wherein the bonding wire of the first internal bias line has a length substantially equal to lengths of the bonding wires of the other internal bias liens, and the first pattern of the first internal bias line has a length longer than lengths of the first patterns of the other internal bias lines.

3 . The optical transceiver of claim 2 ,
wherein the resistor of the first internal bias line and the resistors of the other internal bias lines are a type of a thin film resistor formed on the wiring substrate.

4 . The optical transceiver of claim 2 ,
wherein the internal bias liens further include respective second patterns on the wiring substrate, and wherein the capacitor of the first internal bias line and the capacitors of the other internal bias lines are mounted outside of the wiring substrate and connected to the second patterns on the wiring substrate by respective bonding wires.

5 . The optical transceiver of claim 4 ,
wherein the wiring substrate further provides ground patterns, wherein the internal bias lines further include other capacitors mounted on the respective ground patterns on the wiring substrate, the other capacitors having capacitance smaller than capacitance of the capacitors mounted outside of the wiring substrate.

6 . The optical transceiver of claim 4 ,
wherein the wiring substrate further provides ground patterns, wherein the internal bias lines further include other capacitors mounted on the respective ground patterns on the wiring substrate, the other capacitors being connected to the respective second patterns on the wiring substrate by bonding wires.

7 . The optical transceiver of claim 6 ,
wherein the bonding wires connecting the second patterns to the other capacitors on the mounting substrate has lengths substantially equal to each other.

8 . The optical transceiver of claim 6 ,
further providing third patterns on the wiring substrate, the third patterns mounting the respective PDs thereon by an arrangement of a back-side illumination.

9 . The optical transceiver of claim 8 ,
further including a carrier that mounts the wiring substrate thereon, wherein the carrier further mounts trans-impedance amplifiers thereon each connected to the respective PDs.

10 . The optical transceiver of claim 9 ,
wherein the trans-impedance amplifiers are connected to the respective PDs through bonding wires.

11 . The optical transceiver of claim 2 ,
further including an external dummy line disposed between the signal lines and the first external bias line in an outside of the optical receiver module, and an internal dummy line in an inside of the optical receiver module, wherein the internal dummy line provides an auxiliary terminal, a first pattern, a resistor, a second pattern, and a capacitor; the first pattern, the resistor, and the second pattern of the internal dummy line being provided on the wiring substrate, the capacitor of the internal dummy line being mounted on an outside of the wiring substrate, the auxiliary terminal connecting the external dummy line to the internal dummy line, the bonding wire connecting the auxiliary terminal to the first pattern of the internal dummy line, and wherein the bonding wire and the first pattern of the internal dummy line have a total length shorter than the lengths of the inner bias lines.

12 . The optical transceiver of claim 11 ,
further including another external dummy line disposed between the first bias line and one of the other bias lines closest to the first bias line in the outside of the optical receiver module, and another internal dummy line in the inside of the optical receiver module, wherein the other internal dummy line includes an auxiliary terminal, a first pattern, a resistor, a second pattern, and a capacitor; the first pattern, the resistor, and the second pattern of the other internal dummy line being provided on the wiring substrate; the capacitor of the other internal dummy line being mounted on the outside of the wiring substrate; the auxiliary terminal of the other internal dummy line connecting the other external dummy line to the other internal dummy line, the bonding wire of the other internal dummy line connecting the auxiliary terminal of the other internal dummy line to the first pattern of the other internal dummy line, and wherein the bonding wire and the first pattern of the other internal dummy line have a total length shorter than the lengths of the inner bias lines.

Assignees

• Sumitomo Electric Industries

Inventors

• Kasai Shinta
• Nakajima Fumihiro
• Ono Masaaki

Classifications

• H10W72/5449

  not being orthogonal to a side surface of the chip, e.g. fan-out arrangements · CPC title

• H04B10/40 Primary

  Transceivers · CPC title

• H03H7/0138

  Electrical filters or coupling circuits · CPC title

• H05K1/025

  Impedance arrangements, e.g. impedance matching, reduction of parasitic impedance (H05K1/024 and H05K1/0243 take precedence; for semiconductor devices H10W44/20) · CPC title

• H04J14/02

  Wavelength-division multiplex systems · CPC title