Richard Mateman

On-chip visible-to-infrared supercontinuum generation with more than 495 THz spectral bandwidth

We report ultra-broadband supercontinuum generation in high-confinement Si3N4 integrated optical waveguides. The spectrum extends through the visible (from 470 nm) to the infrared spectral range (2130 nm) comprising a spectral bandwidth wider than 495 THz, which is the widest supercontinuum spectrum generated on a chip.

High confinement, high yield Si3N4 waveguides for nonlinear optical applications

In this paper we present a novel fabrication technique for silicon nitride (Si(3)N(4)) waveguides with a thickness of up to 900 nm, which are suitable for nonlinear optical applications. The fabrication method is based on etching trenches in thermally oxidized silicon and filling the trenches with Si(3)N(4). Using this technique no stress-induced cracks in the Si(3)N(4) layer were observed resulting in a high yield of devices on the wafer. The propagation losses of the obtained waveguides were measured to be as low as 0.4 dB/cm at a wavelength of around 1550 nm.

All-Optical Full-Band RF Receiver Based on an Integrated Ultra-High-Q Bandpass Filter

Ultra-broadband radiofrequency (RF) receivers are required in higher frequency-band wireless communications, radar communications or multi-band applications in radio telescopes. Such ultra-broadband receivers are inherently difficult to establish with electronics because of limits in the bandwidth of the devices. Photonic means of RF photonic receivers/frontends can overcome the bandwidth limitation in electrical receivers. One aspect that should be considered is the precise signal processing in the optical domain. Here, a full-band (from the L-band to the W-band) all-optical RF receiver based on the Si3N4 microring filter is proposed and experimentally demonstrated. The resolution and processing range of the filter are lower than 420 MHz and larger than 112.9 GHz (FSR larger than 225.78 GHz), respectively, and the out-band suppression of this filter is greater than 40 dB. The center frequency of the filter can be altered for more than one FSR by tuning the phase-shifter on top of the ring. The performance of the full-band all-optical RF-receiver has been discussed, and the spurious free dynamic range of the receiver from the L-band to the Ka-band (limited by the bandwidth of the modulator in our experiment) has been measured to be larger than 111.6 dB·Hz2/3.

Si 3 N 4 -Based Integrated Optical Analog Signal Processor and Its Application in RF Photonic Frontend

Digital signal processing has achieved great success in the field of signal processing over the past several decades. However, as the bandwidth requirement increases, the power consumption and effective number of bits (ENOB) of the analog-to-digital convertor (ADC) have become bottlenecks. One solution is returning to analog and applying microwave photonic technologies, which shows potential for multiband signal processing. In this paper, a programmable integrated analog photonic signal processor based on cascaded Mach-Zehnder interferometers (MZIs) and a channelized filter has been proposed. Different shapes of the signal processor can be acquired for different applications. The highest processing resolution is 143 MHz, and the processing range of the signal processor can be higher than 112.5 GHz. An application of the signal processor for the signal extraction in a radio frequency (RF) photonic frontend operating from L-band to K-band is presented.

Ultra-low-power stress-optics modulator for microwave photonics

In this work, we demonstrate the first stress-optic modulator in a silicon nitride-based waveguide platform (TriPleX) in the telecommunication C-band. In our stress-optic phase modulator the refractive index of the waveguiding materials is controlled by the stress-optic effect induced by actuating a 2 μm thick PZT layer on top of the TriPleX waveguide geometry. The efficiency of the modulator is optimized by, amongst others, focusing the applied stress in the waveguide core region through a local increase of the top cladding. Using a Mach-Zehnder interferometer, we measured a half-wave voltage, Vπ, at 34 V at a wavelength of 1550 nm using a modulator with a total length of 14.8 mm. The measured static power consumption of our stress-optic modulator is in the μW-region as it is only determined by small leakage currents (< 0.1 μA), while the dynamic power consumption at a rise time of 1 ms (1 kHz excitation) is less than 4 mW per modulator. The stress optical modulator goes with an excess loss of 0.01 dB per modulator only. This is in line with the typical low loss characteristics of TriPleX waveguides, being < 0.1 dB/cm at a wavelength of 1550 nm. These specifications make stress-optic modulators an excellent choice for next generation optical beam forming networks with a large number of actuators in silicon photonics in general and in the TriPleX platform in particular.

Ultra-low-power stress-based phase actuator for microwave photonics

The next generation of applications in integrated microwave photonics[1], such as optical beam forming networks or programmable photonic processors[2], requires complex chip designs with hundreds or even thousands of actuators and low propagation losses. While passive material platforms such as silicon nitride possess ultra-low losses in the telecommunication C-Band, today their on-chip phase actuation, however, is solely based on thermo-optic tuners and, hence, suffering from huge power dissipation.

Ultra-broadband supercontinuum generation at telecommunication wavelengths in dispersion engineered stoichiometric Si 3 N 4 waveguides

We demonstrate the generation of ultra-broadband supercontinua in Si<inf>3</inf>N<inf>4</inf> waveguides at a pump wavelength of 1560nm. The supercontinuum extends to beyond 2.6 μm wavelength in the infrared and has a spectral width of more then 453 THz.