System and method for heterodyne coherent detection with optimal offset
US9209908B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 2013 |
| Grant date | Dec 8, 2015 |
| Priority date | — |
| Expiry date | Feb 4, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/64
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A heterodyne optical signal detector and method performed thereby, the signal detector including an optical signal spectrum shaper operable to modify the shape of the frequency spectrum of a received optical signal, a laser local oscillator (LO), and polarization beam splitters (PBSs) to divide the signal and the LO into orthogonal components, waveguides in which intermediate frequency (IF) signals are formed, balanced photodetectors (BPDs) arranged to receive the IF signals and operable to convert the IF signals into electric signals, and analog to digital converters (ADCs) that digitize the electric signals. In embodiments, the ADCs have a predetermined bandwidth, the received signal has a spectrum which, if not shaped, would produce IF signals with a bandwidth greater than that of the ADCs, the spectrum shaper modifies the received signal spectrum to produce IF signals that have a bandwidth substantially equal to half the bandwidth of the ADCs, the laser frequency is adjusted produce IF signals in the waveguides having a frequency spectrum centered at the midpoint of the ADCs' bandwidth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.