Optical modulating device, optical transmitting apparatus using the same, method of controlling optical modulating device, and control program recording medium
US7308210B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 3, 2003 |
| Grant date | Dec 11, 2007 |
| Priority date | — |
| Expiry date | Feb 10, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/50575
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An optical modulating device including a driving circuit generating a driving voltage corresponding to an input signal, an oscillator generating a signal having a low frequency signal lower than that of the input signal, an MZ modulator receiving a DC bias voltage superposed with the low frequency signal and the driving voltage, to generate a modulated optical signal according to the input signal, a photoelectric converting unit for converting the modulated optical signal into an electric signal, a low frequency signal detecting circuit which extracts the low frequency signal component contained in the electric signal, multiplies the low frequency signal component by the low frequency signal outputted by the low frequency oscillator, and then extracts a DC component from a multiplied output signal, and a control circuit for extracting a maximized DC component from the low frequency signal detecting circuit by controlling the DC bias voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.