Optical modulator

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

Linearized modulator for suboctave-bandpass optical analog links

Abstract: The spurious-free dynamic range of a suboctave externally modulated optical analog link can be improved (to >140 dB Hz/sup 4/5/) with modest received optical power and little noise figure penalty by using a simple linearized modulator. Its design consists of two standard Mach-Zehnder interferometric modulators in series, and so can operate at microwave frequencies. This paper develops standardized measures of linearized modulator performance, and uses them to evaluate the modulator; link examples are also given. A simple experiment verifies the basic theoretical predictions. >

Electron-beam-tunable interference filter spatial light modulator.

Abstract: A new type of electron-beam-addressed spatial light modulator has been demonstrated. It is based on the local tuning of an optothermal nonlinear interference filter by the scanned electron beam. Such an e-beam-tunable interference filter device should find applications in both display technology and optical data processing.

Optical wavelength converter

Abstract: In accordance with the invention there is provided an optical wavelength conversion device The conversion device comprises a micro-structured optical waveguide, which includes sections with a non-linear material having an index of refraction which changes as a non-linear function of light intensity The optical waveguide includes a light guiding core region, and the waveguide is dimensioned for providing spatial overlap between the sections filled with the non-linear material and light propagating within the waveguide The conversion device further comprises a first optical light source for introducing light into the waveguide in a mode guided along the core, and a second intensity modulated light source for introducing encoding light into the waveguide in such a manner that it illuminates the sections filled with a non-linear material The second light source has an intensity modulation sufficient to change the refractive index of the non-linear material by an amount sufficient to encode or modulate the light from the first optical light source accordingly, whereby the encoding takes place through the effect of leaking light from the first light source from the inside of the guiding core to the outside of the guiding core The micro-structured optical waveguide may comprisean optical fibre, in which the light from the first light source may be guided by different types of waveguiding principles including total internal reflection or by photonic bandgap effects In an alternative embodiment the micro-structured optical waveguide may comprise an optical planar waveguide The conversion device includes embodiments in which the encoding light from the secondlight source and the light to be encoded or modulated from the first light source are co-propagating, are counter-propagating, or where the encoding light has a propagation direction different to the propagation direction of the light to be encoded According to the invention there is also provided a micro-structured optical waveguide, which may have an axial direction, which waveguideincludes sections that are elongated in the axial direction and comprise a non-linear material having an index of refraction whichchanges as a non-linear function of light intensity This optical waveguide, which may be an optical fibre, includes a light guiding core region, and the waveguide is dimensioned for providing spatial overlap between the sections filled with the non-linear material and light propagating within the waveguide There is furthermore provided an optical switching device and an optical intensity limiting device which may be based on the micro-structured optical waveguide of the invention

56 Gb/s Germanium Waveguide Electro-Absorption Modulator

Abstract: We report a Germanium waveguide electro-absorption modulator with electro-optic bandwidth substantially beyond 50 GHz. The device is implemented in a fully integrated Si photonics platform on 200 mm silicon-on-insulator wafers with 220 nm top Si thickness. Wide open eye diagrams are demonstrated at 1610 nm operation wavelength for nonreturn-to-zero on-off keying (NRZ-OOK) modulation at data rates as high as 56 Gb/s. Dynamic extinction ratios up to 3.3 dB are obtained by applying drive voltages of 2 V peak-to-peak, along with an optical insertion loss below 5.5 dB. The device has a low junction capacitance of just 12.8 fF, resulting in 12.8 fJ/bit of dynamic and ∼1.2 mW of static power consumption in typical operating conditions. Wafer-scale performance data are presented and confirm the manufacturability of the device. The demonstrated modulator shows great potential for realizing high-density and low-power silicon photonic transceivers targeting short-reach optical interconnects at serial data rates of 56 Gb/s and beyond.

3-D integration of MQW modulators over active submicron CMOS circuits: 375 Mb/s transimpedance receiver-transmitter circuit

Abstract: We accomplish the integration of GaAs-AlGaAs multiple quantum well modulators directly on top of active silicon CMOS circuits. This enables optoelectronic VLSI circuits to be achieved and also allows the design and optimization of the CMOS circuits to proceed independently of the placement and the bonding of surface-normal optical modulators to the circuit. Using this technique, we demonstrate operation of a 0.8 micron CMOS transimpedance receiver-transmitter circuit at 375 Mb/s. >