Optical Waveform Sampling and Error-free Demultiplexing of 1.28 Tbit/s Serial Data in a Silicon Nanowire

Nonlinear properties of and nonlinear processing in hydrogenated amorphous silicon waveguides

“…When the duty cycle of the sampling pulse train (−43 dB) is taken into account, the intrinsic conversion efficiency η is found to be + 12 dB. This is an improvement of almost 19.5 dB as compared to a similar optical sampling system based on c-Si [20], where the intrinsic conversion efficiency was found to be merely −7.5 dB.…”

Nonlinear optical interactions in silicon waveguides

“…In another experiment, the waveguides were also used in an all-optical signal processing experiment [33]. In this experiment, a 320 Gbit/s signal was sampled with an efficiency over 100 times stronger than could be achieved in crystalline silicon [40]. In our group, we have observed that the a-Si:H layers are photo-sensitive when using telecom-band pump pulses.…”

Optical waveform monitoring based on a free-running mode-locked femtosecond fibre laser and four-wave mixing in a highly nonlinear fibre

“…At present, all−optical waveform sampling is normally im− plemented by exploiting the nonlinear optical effects in opti− cal media such as optical fibres [1,2,7], waveguides [3,12,13] and crystals [4,5]. These include the second−order susceptibil− ity c 2 in nonlinear crystals (e.g., KTiOPO 4 (KTP) [14,15] and periodically poled LiNbO 3 (PPLN) crystals [4,5]) and the third−order susceptibility c 3 (e.g., cross−phase modulation and four−wave mixing) in nonlinear optical fibres [1,2,16], semiconductor optical amplifiers (SOAs) [3,17], and silicon nanowire [12] or chalcogenide planar waveguide [13], respec− tively.…”

“…These include the second−order susceptibil− ity c 2 in nonlinear crystals (e.g., KTiOPO 4 (KTP) [14,15] and periodically poled LiNbO 3 (PPLN) crystals [4,5]) and the third−order susceptibility c 3 (e.g., cross−phase modulation and four−wave mixing) in nonlinear optical fibres [1,2,16], semiconductor optical amplifiers (SOAs) [3,17], and silicon nanowire [12] or chalcogenide planar waveguide [13], respec− tively. Nevertheless, those schemes can have their individual advantages and respective drawbacks in terms of operational speed, wavelength range, manufacturing cost, complexity and physical size of the resulting optical waveform samplers (also called sampling gates).…”

“…On the other hand, if the SOA−based waveform samplers are used, their operational speed can be ultimately limited by the rela− tively long gain recovery time in SOAs, and the amplified spontaneous emission noise of a SOA can also cause a degra− dation of signal−to−noise ratio for the optically sampled signal. Moreover, optical samplers based on advanced silicon nano− wire and chalcogenide planar waveguide are promising for optical waveform monitoring, as they are capable of ultra− high−speed operations and integrated implementation on a sin− gle photonic chip [12,13]. However, these chip−scale optical samplers require a sophisticated fabrication process which can prevent them from practical applications nowadays.…”