Transmitter optical module outputting an optical signal containing two or more wavelengths

Abstract

A transmitter module is disclosed, where the transmitter module includes optical sources, an optical multiplexer to multiple optical signals each output from optical sources, an optical detector to detect an output of the optical multiplexer, and a controller. The controller alternately superposes a dither signal on a bias current provided to the optical source, and the bias current is controlled based on a magnitude of the dither signal, which is detected by a configuration similar to the lock-in amplifier.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present application relates to a transmitter optical module that outputs an optical signal containing two or more wavelengths.[0003]2. Related Background Art[0004]Recent optical communication has continuously requested to increase the capacity thereof drastically. Conventional systems, such as the full-duplex system, do not give a satisfactory solution for the request above. One practical solution is the wavelength division multiplexing (WDM) system where two or more optical signals each having a specific wavelength different from others are wavelength multiplexed and thus multiplexed optical signal is transmitted through a single fiber. The QSFP+ standard, which is one of multi-source agreements for a pluggable optical transceiver, has ruled that four optical signals each having a wavelength in 1.3 μm band and a transmission speed of 10 Gbps or 25 Gbps are multiplexed to realize a total speed of 40 Gbps or 100 Gbps...

AI Technical Summary

Benefits of technology

The present patent relates to a transmitter optical module that has the function of wavelength multiplexing. This module includes multiple optical sources, an optical multiplexer, an optical detector, an extractor, and a controller. The electrical signal is superposed on the bias current and the extractor extracts a specific component with a specific frequency. The controller determines the bias current based on the extracted component. The key feature is that each APC has its own extractor. This allows for the detection of optical signals unique to each LD. The present patent provides various examples and arrangements of the transmitter optical module to facilitate the reading of R&D personnel.

Problems solved by technology

Conventional systems, such as the full-duplex system, do not give a satisfactory solution for the request above.

When optically active devices, half of which emit optical signals; while, the rests monitor respective optical output power, are concurrently installed in a housing, entanglement between the light emitting devices and light receiving devices becomes a problem.

However, a request to make the size in compact is always raised even when an optical transceiver has the wavelength multiplexing function, which inevitably causes the accuracy of the monitored output power of the optical sources.

That is, when the optical output of a target device is to be monitored, the devices except for the target device always influences the monitored output power, which degrades the accuracy of the detection and causes the poor control of the optical output power.

Images