Optical modulator

About: Optical modulator is a research topic. Over the lifetime, 14068 publications have been published within this topic receiving 196932 citations.

Tunable Electro-Optical Modulator Based on a Photonic Crystal Fiber Selectively Filled With Liquid Crystal

Abstract: A liquid-crystal-filled photonic crystal fiber (PCF) is proposed for electro-optical modulation. The E7 liquid crystal is precisely filled in one of the innermost air holes of the PCF and forms an in-fiber optical coupler, and the resonance wavelength can be tuned with a sensitivity of 5.594 nm/ V rms when an external voltage is applied. The device can operate as an electro-optical switch/modulator and exhibits response and recovery times of approximately 47 and 24 ms, respectively from 1414 nm to more than 1700 nm. The proposed structure is expected to have potential applications in electric field sensing and wavelength-tunable electro-optical devices.

Broadband wavelength-tunable ultrashort pulse source using a Mach-Zehnder modulator and dispersion-flattened dispersion-decreasing fiber

Abstract: The broadband wavelength tunability of femtosecond pulse generation using a Mach-Zehnder-modulator-based flat-comb generator (MZ-FCG) and a dispersion-flattened dispersion-decreasing fiber (DF-DDF) was demonstrated. Near-Fourier-transform-limit picosecond pulses generated from the MZ-FCG were compressed into femtosecond pulses by adiabatic soliton compression. By tuning the wavelength of the input cw light, 200 fs, 10 GHz pulses were generated in the wavelength range of 1,535 to 1,570 nm. Such wide-range wavelength tunability was realized by both the independence of a comb-flattening condition from the inputted wavelength and the dispersion flatness of the DF-DDF.

Method for optical carrier suppression and quadrature control

Abstract: A suppressed carrier optical communications signal is generated by driving (biasing) an optical modulator capable of complex modulation of an optical carrier signal to a bias point near a zero-crossing point of the modulator's E-field response. A complex input signal is then used to drive excursions of the E-field response to impress the input signal onto the optical carrier. The resulting lightwave emerging from the complex modulator exhibits an optical spectrum characterized by a pair of sidebands and a strongly suppressed carrier. Bias control of the complex modulator is implemented on the basis of the optical power detected at the output of the complex modulator. This enables the optical modulator to be treated as a “black box”, in that calculation of the bias signals does not relay on knowledge of the precise performance characteristics of the modulator.

Harnessing nonlinearities near material absorption resonances for reducing losses in plasmonic modulators

Abstract: The electro-optic coefficient (Pockels coefficient) is largest around the absorption resonance of a material Here, we show that the overall losses, the power consumption and the footprint of plasmonic electro-optic modulators can be reduced when a device is operated in the vicinity of absorption resonances of an electro-optical material This near-resonant operation in plasmonics is contrary to what is known from photonics where off-resonant operation is required to minimize the overall losses The findings are supported by experiments demonstrating a reduction in voltage-length product by a factor of 3 and a reduction in loss by a factor 2 when operating a plasmonic modulator near resonance compared to off-resonant

Silicon photonic modulators for PAM transmissions

Abstract: High-speed optical interconnects are crucial for both high performance computing and data centers. High power consumption and limited device bandwidth have hindered the move to higher optical transmission speeds. Integrated optical transceivers in silicon photonics using pulse-amplitude modulation (PAM) are a promising solution to increase data rates. In this paper, we review recent progress in silicon photonics for PAM transmissions. Copyright (c) 2018 IOP. Personal use is permitted. For any other purposes, permission must be obtained from the IOP by emailing permissions@iop.org.