Configurable chirp mach-zehnder optical modulator
US5991471A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 9, 1998 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Apr 9, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/25
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A Mach-Zehnder optical modulator is provided having first and second modulation electrodes on respective first and second interferometric arms for receiving modulating electric fields, and the two modulation electrodes are of different lengths, the ratio of the lengths being designed to control the relative bias of the two arms, thereby provide for adjustment and optimization of frequency chirp, in a positive or negative chirp MZ modulator or in a configurable chirp MZ modulator. The modulator may have an asymmetric input y-junction coupler and an asymmetric output y-junction coupler to provide unequal power splitting, and interferometric arms defining two optical paths, which may be of equal or unequal length so as to generate a fixed phase difference of 0, .pi. or .pi./2. Preferably, the device is operated with equal push-pull drive, although non-equal push pull drive may alternatively be used. The asymmetric modulation electrodes may be used in combination with an additional control electrode or pair of control electrodes, and with equal or non-equal power splitting. This structure is applicable to either semiconductor MZ modulators or lithium niobate MZ modulators, and provides…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.