Optical modulator

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

High-speed binary optically addressed spatial light modulator

Abstract: We describe the structure and operating characteristics of a high‐speed optically addressed spatial light modulator (OASLM) with a hydrogenated amorphous silicon (a‐Si:H) photosensor and a ferroelectric liquid‐crystal modulator. The photosensor is a p‐i‐n photodiode, which switches the liquid crystal into one of two stable states. Under a write‐light intensity of 6 mW/cm2, the OASLM exhibits a response time of 155 μs, a contrast ratio of 20:1, and a resolution of 40 lp/mm. The writing sensitivity per pixel is 0.1 pJ.

Silicon waveguide modulator based on carrier depletion in periodically interleaved PN junctions

Abstract: We present the design and numerical simulation results for a silicon waveguide modulator based on carrier depletion in a linear array of periodically interleaved PN junctions that are oriented perpendicular to the light propagation direction. In this geometry the overlap of the optical waveguide mode with the depletion region is much larger than in designs using a single PN junction aligned parallel to the waveguide propagation direction. Simulations predict that an optimized modulator will have a high modulation efficiency of 0.56 V.cm for a 3V bias, with a 3 dB frequency bandwidth of over 40 GHz. This device has a length of 1.86 mm with a maximum intrinsic loss of 4.3 dB at 0V bias, due to free carrier absorption. (C) 2009 Optical Society of America

Method and apparatus providing optical input/output through the back side of an integrated circuit die

Abstract: A method and an apparatus providing optical input/output in an integrated circuit. In one embodiment, optical modulators and demodulators, which are coupled to integrated circuit input/output nodes, are disposed on or within the back side semiconductor substrate of a flip chip packaged integrated circuit. Since a flip chip packaged integrated circuit die is utilized, full access to the optical modulators and demodulators is provided from the back side of the integrated circuit die for optical input/output. In one embodiment, a heat sink including a light source and an optical assembly is thermally and optically coupled to the back side of the integrated circuit die. A light beam is directed to the optical modulators and the deflected modulated light beam is routed and directed to the optical demodulators to realize optical input/output. In one embodiment, infrared light may be utilized such that the optical modulators and demodulators are disposed within a silicon semiconductor substrate. Since silicon is partially transparent to infrared light, optical input/output is realized through the back side and through the semiconductor substrate of the flip chip packaged integrated circuit die.

Silicon Mach–Zehnder waveguide interferometers based on the plasma dispersion effect

Abstract: Silicon Mach–Zehnder waveguide modulators have been fabricated and operation characterized at the wavelength of 1.3 μm. Device operation is based on the free‐carrier‐induced change in the refractive index of silicon. Modulation depths of −4.9 dB and response times τresponse<50 ns have been achieved at λ=1.3 μm for an injected carrier density of 6.5×1017 cm−3.

Efficient microwave frequency conversion using photonic link signal mixing

Abstract: An efficient, high-dynamic range microwave mixer implemented using an analog fiber-optic link with an overdriven optical modulator to produce the local oscillator requirement has been demonstrated and analyzed. This approach is compared with the heterodyned lasers approach to generating the local oscillator requirement and it is shown that increased conversion efficiency and more frequency and phase stable upconverted or downconverted signals are obtainable. Aside from RF link loss, which can be compensated with preamplification, a conversion loss below 5 dB has been demonstrated out to 10 GHz.