Optical modulator

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

A Silicon Modulator Enabling RF Over Fiber for 802.11 OFDM Signals

Abstract: We investigate the linearity properties of silicon modulators and show that, contrary to the traditional lithium niobate Mach-Zehnder modulators (MZMs), the third-order intermodulation distortion (IMD3) for silicon modulators is a function of the modulator bias point. The bias point for silicon modulators can be chosen to reduce the IMD3 well below that of standard lithium niobate MZMs. Given the cost and integration advantages of the silicon photonics technology, silicon modulators offer significant advantages for emerging radio over fiber applications. As an example, we examine, for the first time to our knowledge, a silicon modulator for converting analog 802.11 RF signals to the optical domain, achieving an error vector magnitude of -30 dB.

High-efficiency Si optical modulator using Cu travelling-wave electrode

Abstract: We demonstrate a high-efficiency and CMOS-compatible silicon Mach-Zehnder Interferometer (MZI) optical modulator with Cu traveling-wave electrode and doping compensation. The measured electro-optic bandwidth at Vbias = -5 V is above 30 GHz when it is operated at 1550 nm. At a data rate of 50 Gbps, the dynamic extinction ratio is more than 7 dB. The phase shifter is composed of a 3 mm-long reverse-biased PN junction with modulation efficiency (Vπ·Lπ) of ~18.5 V·mm. Such a Cu-photonics technology provides an attractive potentiality for integration development of silicon photonics and CMOS circuits on SOI wafer in the future.

Intrinsic multiple quantum well spatial light modulators

Abstract: Large improvements are reported in the sensitivity of optically addressed multiple quantum well spatial light modulators. In prior work with these materials the quantum well region has been made semi‐insulating. It is shown that this is unnecessary and in fact detrimental to performance. By placing layers containing high trap concentrations at the ends of the structure and leaving the active quantum well layers intrinsic the speed of the device at a given illumination is improved by more than four times, diffraction efficiency is enhanced and spatial resolution is almost the same.

Wide-band acousto-optic light modulator for frequency domain fluorometry and phosphorimetry

Abstract: Multifrequency‐phase and modulation fluorometry allows for accurate analysis of fluorescence decay in the frequency domain. Essential to these frequency domain methods is a high‐frequency modulation of the light source. Techniques for generating wide‐band modulation of light are currently limited to the use of Pockel’s cells and intrinsically modulated sources such as mode‐locked lasers and synchrotron radiation. We present a method that employs two acousto‐optic modulators in series for use with cw light sources. This modulator system gives two orders of magnitude more intensity output than the Pockel’s cell modulator and requires less than one‐tenth of the rf driving power. In addition, the Pockel’s cell system is limited to modulation frequencies less than 250 MHz, whereas the particular implementation discussed here gives a quasicontinuous distribution of modulation frequencies from dc to 320 MHz. To obtain this range of frequencies, acoustic standing waves are set up simultaneously in each modulator,...

Conductive membrane optical modulator

Abstract: An optical waveguide modulator for modulating an optical beam is described. The modulator includes a substrate and a waveguide formed in or on the substrate. A plurality of conductive membranes which define an array each being effective in a first position to be spaced from the waveguide and located along the waveguide, and in a second position to be closer to or to engage the waveguide so that when in the second position, the optical absorption properties of the waveguide changes.