Topic
Extinction ratio
About: Extinction ratio is a research topic. Over the lifetime, 8541 publications have been published within this topic receiving 111908 citations.
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TL;DR: All-optical switching in oxygen ion implanted silicon microring resonators is presented and the influence of implantation dose on the switching speed and additional propagation losses of the silicon waveguide--the latter as a result of implantations induced amorphization--is carefully evaluated and in good agreement with theoretical predictions.
Abstract: We present all-optical switching in oxygen ion implanted silicon microring resonators. Time-dependent signal modulation is achieved by shifting resonance wavelengths of microrings through the plasma dispersion effect via femtosecond photogeneration of electron-hole pairs and subsequent trapping at implantation induced defect states. We observe a switching time of 25 ps at extinction ratio of 9 dB and free carrier lifetime of 15 ps for an implantation dose of 7×1012 cm-2. The influence of implantation dose on the switching speed and additional propagation losses of the silicon waveguide – the latter as a result of implantation induced amorphization – is carefully evaluated and in good agreement with theoretical predictions.
116 citations
TL;DR: Numerical simulations with a full vectorial beam propagation method demonstrate that it is possible to obtain a 1.9-mm-long splitter with the extinction ratio better than -20 dB and a bandwidth of 37nm.
Abstract: A novel design of polarization splitter in three-core photonic crystal fibers (PCFs) has been proposed. The three-core PCF consists of two given identical cores with two-fold symmetry separated by a core with high birefringence. The polarization splitter is based on the phenomenon of resonant tunneling. Numerical simulations with a full vectorial beam propagation method demonstrate that it is possible to obtain a 1.9-mm-long splitter with the extinction ratio better than -20 dB and a bandwidth of 37 nm.
116 citations
TL;DR: In this article, the operation of a two-pump parametric optical regenerator is described and the spectral broadening of the higher order terms can be controlled in amplifiers by using counterphased optical pumps.
Abstract: We describe the operation of a two-pump parametric optical regenerator. It is shown that higher order parametric coupling provides optical regeneration with a high extinction ratio. Excessive spectral broadening is studied in a two-pump architecture and compared with that of the one-pump parametric regenerator. We show that the spectral widths of the higher order terms can be controlled in amplifiers by using counterphased optical pumps.
115 citations
TL;DR: The high speed operation of a Ge/SiGe multiple quantum well (MQW) electro-absorption modulator in a waveguide configuration demonstrates the potentiality of Ge/ SiGe MQWs as a building block of silicon compatible photonic integrated circuits for short distance energy efficient optical interconnections.
Abstract: We report on high speed operation of a Ge/SiGe multiple quantum well (MQW) electro-absorption modulator in a waveguide configuration. 23 GHz bandwidth is experimentally demonstrated from a 3 µm wide and 90 µm long Ge/SiGe MQW waveguide. The modulator exhibits a high extinction ratio of more than 10 dB over a wide spectral range. Moreover with a swing voltage of 1 V between 3 and 4 V, an extinction ratio as high as 9 dB can be obtained with a corresponding estimated energy consumption of 108 fJ per bit. This demonstrates the potentiality of Ge/SiGe MQWs as a building block of silicon compatible photonic integrated circuits for short distance energy efficient optical interconnections.
115 citations
TL;DR: In this paper, an analytical theory describing all-optical wavelength converters based on cross-gain modulation (XGM) in semiconductoroptical amplifiers is derived, which consists of two parts: a large-signal analysis yielding the transmission function for the signal, and a small signal analysis in order to describe the transformation of the signal and probe intensity noise.
Abstract: An analytical theory describing all-optical wavelength converters based on cross-gain modulation (XGM) in semiconductor-optical amplifiers is derived. Our theory consists of two parts: a large-signal analysis yielding the transmission function for the signal, and a small-signal analysis in order to describe the transformation of the signal and probe intensity noise. Both the large-signal as well as the small-signal theory reveal similar performance for the co- and the counterpropagating injection scheme for bit rates up to 2.5 Gb/s. This is confirmed by computer simulations. Consequently, the counterpropagating configuration is preferable because the implementation is simpler and conversion to the same wavelength is possible. In order to increase the conversion efficiency it is better to reduce the average signal power than to increase the probe power, which additionally reduces the output power range. However, there is a tradeoff between conversion efficiency and output extinction ratio. According to the small-signal analysis, the relative-intensity noise (RIN) due to the probe and due to the amplified spontaneous emission is negligible. Moreover, the converted signal has a lower RIN than the input signal.
114 citations