Title :
Linear 0.20 GHz modulation with a 1*2 directional coupler
Author :
Bulmer, C.H. ; Burns, W.K. ; Pickett, C.W.
Author_Institution :
US Naval Res. Lab., Washington, DC, USA
Abstract :
The design and performance of a traveling-wave 1*2 directional coupler modulator are described. A 0-20 GHz response (-4 dB/sub e/) was achieved for Ti:LiNbO/sub 3/ devices at the 1.3- mu m wavelength. From experimental determinations of coupling coefficient and interarm intrinsic phase-mismatch for several modulators, linear dynamic ranges of, on average, 78 dB and voltage sensitivities of down to 9 mu V are determined (for 1-mW detector power, 3-kHz bandwidth, 50- Omega detector load). The dependence of sensitivity on the coupling coefficient is described, and the effect of the buffer layer thickness on the optical bandwidth and sensitivity is demonstrated.<>
Keywords :
directional couplers; integrated optics; lithium compounds; optical couplers; optical modulation; titanium; 0 to 20 GHz; 1 mW; 1*2 directional coupler; 1.3 micron; 3 kHz; 9 muV; LiNbO/sub 3/:Ti; buffer layer thickness; coupling coefficient; detector load; interarm intrinsic phase-mismatch; linear dynamic ranges; linear optical modulation; optical bandwidth; travelling-wave coupler modulator; voltage sensitivities; Bandwidth; Buffer layers; Detectors; Directional couplers; Dynamic range; Optical buffering; Optical coupling; Phase detection; Phase modulation; Voltage;
Journal_Title :
Photonics Technology Letters, IEEE
