We demonstrate a bulk silicon alternative to the conventional silicon-on-insulator photonics platform, using common CMOS process-based Si3N4 masking and oxidation techniques. We show waveguide losses as low as 2.92 dB/cm with a technique that can be implemented on the front-end of a typical CMOS fabrication line.
A novel on-chip spectrometer device using combined functionalities of a micro-ring resonator and a planar diffraction grating is proposed. We investigate the performance of this architecture by implementing it in a silicon-on-insulator platform. We experimentally demonstrate such a device with 100 channels, 0.1 nm channel spacing and a channel crosstalk less than -10 dB. The entire device occupies an area of less than 2 mm2. Based on our initial results we envision that this device enables the possibility of the realization of low-cost and high-resolution ultra-compact spectroscopy.
We demonstrate a temporal imaging system based on parametric mixing that allows simple triggering from an external clock by using a time-lens-based pump laser. We integrate our temporal imaging system into a time-to-frequency measurement scheme and demonstrate the ability to perform characterization of temporal waveforms with 1.4-ps resolution and a 530-ps record length. We also integrate our system into a temporal-magnification scheme and demonstrate single-shot operation with a 113 x magnification factor, 1.5-ps resolution, and 220-ps record length.
We report 50 Gbit/s modulation capability using four silicon micro ring modulators within a footprint of 500 um2. This is the highest total modulation capability shown in silicon using compact micro-ring modulators. Using the proposed techniques, silicon nanophotonic bandwidths can meet the requirements of future CMOS interconnects by using multiple wavelengths to extend beyond single device speeds.
We report experimental demonstration of an all-optical continuously tunable delay line based on parametric mixing with a total delay range of 7.34 us. The bit-error rate performance of the delay line was characterized for a 10-Gb/s NRZ data channel. This result is enabled by cascading a discrete delay line that consists of 16 wavelength-dependent delays and a continuously tunable delay stage. Four wavelength conversion stages based on four-wave mixing in silicon waveguides were performed in order to achieve wavelength-preserving operation. The wavelength-optimized optical phase conjugation scheme employed in the delay line is capable of minimizing the residual dispersion for the entire tuning range.
We show GHz modulation in a 2.5 um radius silicon micro-ring, with only 150 mV peak-peak drive voltage and an electro-optic modal volume of only 2 um3. The swing voltage and the micro-ring modulator are the smallest demonstrations so-far in silicon. The presented approach lays the ground work for a new class of high speed low voltage modulators enabling, seamless integration of nanophotonics with low voltage digital CMOS nano-electronics.
We demonstrate reduction of the free-carrier lifetime in a silicon nanowaveguide from 3 ns to 12.2 ps by applying a reverse bias across an integrated p-i-n diode. This observation represents the shortest free-carrier lifetime demonstrated to date in silicon waveguides. Importantly, the presence of the p-i-n structure does not measurably increase the propagation loss of the waveguide. We derive a figure of merit demonstrating equal dependency of the nonlinear phase shift on free-carrier lifetime and linear propagation loss.
We demonstrate a scalable, energy-efficient, and pragmatic method for high-bandwidth wavelength multicasting using FWM in silicon photonic nanowires. We experimentally validate up to a sixteen-way multicast of 40-Gb/s NRZ data using spectral and temporal responses, and evaluate the resulting data integrity degradation using BER measurements and power penalty performance metrics. We further examine the impact of this wavelength multicasting scalability on conversion efficiency. Finally, we experimentally evaluate up to a three-way multicast of 160-Gb/s pulsed-RZ data using spectral and temporal responses, representing the first on-chip wavelength multicasting of pulsed-RZ data.
We demonstrate a distortion free tunable optical delay as long as 135 ps with a 10 GHz bandwidth using thermally tuned silicon microring resonators in the novel balanced configuration. The device is simple, easy to control and compact measuring only 30 mu m wide by 250 mu m long.
We fabricate high-Q arsenic triselenide glass microspheres through a three-step resistive heating process. We demonstrate quality factors greater than 2x10(6) at 1550 nm and achieve efficient coupling via a novel scheme utilizing index-engineered unclad silicon nanowires. We find that at powers above 1 mW the microspheres exhibit high thermal instability, which limits their application for resonator-enhanced nonlinear optical processes. (C) 2009 Optical Society of America
We demonstrate continuously tunable optical delays as large as 1.1 mu s range for 10 Gb/s NRZ optical signals based on four-wave mixing (FWM) process in silicon waveguide. The large delay range is made possible by a novel wavelength-optimized optical phase conjugation scheme, which allows for tunable dispersion compensation to minimize the residual group-velocity dispersion (GVD) for the entire tuning range. (C) 2009 Optical Society of America
We address the primary claim in the Comment by N. Alic et al. that our scheme for generating 1-mu s tunable delays via Si-based waveguides in [Opt. Express 17, 7004-7010 (2009)] cannot support wavelength transparency by showing experimentally that the addition of a third conversion stage to reconvert to the input wavelength has minimal effect on the performance of our delay scheme. (C) 2009 Optical Society of America
We report on the demonstration of a broadband (60 GHz), spectrally hitless, compact (20 mu m x 40 mu m), fast (7 ns) electro-optical switch. The device is composed of two coupled resonant cavities, each with an independently addressable PIN diode. This topology enables operation of the switch without perturbing adjacent channels in a wavelength division multiplexing (WDM) system. (C) 2009 Optical Society of America
The use of optical forces to manipulate small objects is well known. Applications include the manipulation of living cells by optical tweezers(1) and optical cooling in atomic physics(2). The miniaturization of optical systems ( to the micro and nanoscale) has resulted in very compliant systems with masses of the order of nanograms, rendering them susceptible to optical forces(3-6). Optical forces have been exploited to demonstrate chaotic quivering of microcavities(7), optical cooling of mechanical modes(8-11), actuation of a tapered-fibre waveguide and excitation of the mechanical modes of silicon nano-beams(12,13). Despite recent progress in this field(14-17), it is challenging to manipulate the optical response of photonic structures using optical forces; this is because of the large forces that are required to induce appreciable changes in the geometry of the structure. Here we implement a resonant structure whose optical response can be efficiently statically controlled using relatively weak attractive and repulsive optical forces. We demonstrate a static mechanical deformation of up to 20 nanometres in a silicon nitride structure, using three milliwatts of continuous optical power. Because of the sensitivity of the optical response to this deformation, such optically induced static displacement introduces resonance shifts spanning 80 times the intrinsic resonance linewidth.
We present ultra-broadband wavelength conversion in silicon photonic waveguides at a data rate of 40 Gb/s. The dispersion-engineered device demonstrates a conversion bandwidth spanning the entire S-, C-, and L-bands of the ITU grid. Using a continuous-wave C-band pump, an input signal of wavelength 1513.7 nm is up-converted across nearly 50 nm at a data rate of 40 Gb/s, and bit-error-rate measurements are performed on the converted signal.
We demonstrate a micrometer-scale electro-optic modulator operating at 2.5 Gbps and 10 dB extinction ratio that is fabricated entirely from deposited silicon. The polycrystalline silicon material exhibits properties that simultaneously enable high quality factor optical resonators and sub-nanosecond electrical carrier injection. We use an embedded p(+)n(-)n(+) diode to achieve optical modulation using the free carrier plasma dispersion effect. Active optical devices in a deposited microelectronic material can break the dependence on the traditional single layer silicon-on-insulator platform and help lead to monolithic large-scale integration of photonic networks on a microprocessor chip. (C) 2009 Optical Society of America
We demonstrate high confinement, low-loss silicon nitride ring resonators with intrinsic quality factor (Q) of 3*10(6) operating in the telecommunication C-band. We measure the scattering and absorption losses to be below 0.065dB/cm and 0.055dB/cm, respectively. (C) 2009 Optical Society of America
We experimentally demonstrate a spectral magnifier using an imaging system with two time-lenses based on four-wave mixing in a Si nanowaveguide. We achieve a magnification factor of 105 with a frequency resolution of 1 GHz. The system offers potential as a tool for single-shot, high resolution spectral measurements. (C) 2009 Optical Society of America
We report the fabrication and experimental verification of a multiwavelength high-speed 2 x 2 silicon photonic switch for ultrahigh-bandwidth message routing in optical on-chip networks. The structure employs only two microring resonators in order to implement the bar and cross states of the switch. These states are toggled using an optical pump at 1.5-mu m wavelengths in-plane with the waveguide devices, though electronic, rather than optical, control schemes are envisioned for more complex systems built from these devices. Experiments characterize bit-error-rate performance in the bar and cross states during static and dynamic operation. The all-optical demonstration exhibits the ability of the switch to implement ultra-short transition times (<2ns), high extinction ratios (>10 dB), and lowpower penalties (dB) at a data rate of 10 Gb/s. Further performance improvements are expected by using electronic carrier injection via p-i-n diodes surrounding the ring waveguides. The 2 x 2 switching functionality facilitates the design of more complex routing structures, allowing the implementation of high-functionality integrated optical networ ks.
We demonstrate a single-shot technique for optical sampling based on temporal magnification using a silicon-chip time lens. We demonstrate the largest reported temporal magnification factor yet achieved (>500) and apply this technique to perform 1.3 TS/s single-shot sampling of ultrafast waveforms and to 80-Gb/s performance monitoring. This scheme offers the potential of developing a device that can transform GHz oscilloscopes into instruments capable of measuring signals with THz bandwidths. (C) 2009 Optical Society of America