Open AccessElectro‐optic SSB modulator with 90° hybrid directly prepared onto LiNbO 3 substrate
Author(s) -
Enokihara A.,
Kawamura K.,
Nakao T.,
Yamamoto K.,
Kawai T.,
Kawanishi T.
Publication year - 2013
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
ISSN - 1350-911X
DOI - 10.1049/el.2013.1533
Subject(s) - modulation (music) , electro optic modulator , optical modulator , compatible sideband transmission , materials science , phase modulation , optoelectronics , optics , intensity modulation , sideband , signal (programming language) , amplitude modulation , optical modulation amplitude , substrate (aquarium) , frequency modulation , microwave , physics , telecommunications , radio frequency , optical amplifier , computer science , phase noise , programming language , laser , oceanography , acoustics , geology
Optical single‐sideband (SSB) modulation is theoretically realised by applying two modulation signals with a 90° phase difference to the dual‐electrode type electro‐optic (EO) modulator. A branch‐line coupler (BC) as the microwave 90° hybrid was directly prepared on the EO modulator substrate, LiNbO 3 , to create two modulation signals from a single input signal. Output ports of the BC were connected to the modulation electrodes on the substrate. Thereby, an EO optical SSB modulator was realised with a single‐tip and a small‐sized configuration. The SSB modulator was designed and fabricated for around 10 GHz modulation frequency and 1550 nm light wavelength. The optical SSB modulation operation with a sideband suppression ratio of more than 20 dB was confirmed by the experiment.