We demonstrate a device that integrates a III-V semiconductor saturable absorber mirror with a graphene electro-optic modulator, which provides a monolithic solution to modelocking and noise suppression in a frequency comb.
Nanobeam laser with threshold 230 nW is demonstrated in continuous-wave operation at room-temperature. This is achieved by reducing the size of active medium to 1.5×0.3×0.02 μm3 via selective wet-etching of a single quantum well layer.
MIIPS is a popular method for compressing femtosecond pulses. It is not ideal for complex pulses, like those produced by self-phase modulation. We show that several limitations are fixed by an improvement called G-MIIPS.
We report an integrated graphene photodetector on top of a silicon waveguide with a maximum responsivity of 0.36 A/W and a 3dB high-speed cut-off frequency of 42 GHz. Furthermore, nonlinear photocurrent in graphene under pulse excitation enables direct on-chip characterization of ultrafast pulses.
A cross-correlation frequency-resolved optical gating is developed for the characterization of an optical pulse train consisting of monocycle pulses. An optical beat is employed for resolving the ultrafast temporal intensity variation in the train.
Dual-comb spectroscopy using electro-optic-modulator-based frequency combs broadened in a highly nonlinear fiber opens up new opportunities for analytical spectroscopy. One hundred thousand spectra per second are measurable with a 10-THz span and a 157-GHz resolution.
Waveguide-based, electro-optic modulators were used to generate pitch-agile, optical frequency combs from a single continuous-wave laser. These combs are then detected via a multiheterodyne approach where the absorption information is down-converted into the radiofrequency domain.
Mechanics is increasingly recognized as an important factor in numerous biological processes. Monitoring the mechanical properties of cells and tissue is considered a key factor to the understanding of a range of fundamental biological processes.
We propose an on-chip integrated differential optical silicon nitride microring biosensing platform which uses a dual laminar flow scheme. This platform reduces the fabrication complexity involved in the fabrication of the reference resonator.
We convert higher order fiber modes into Gaussian beams using binary phase plates, and characterize the resulting M2 and coupling efficiency to single-mode fiber (∼64%). Reciprocally, the system is used to excite modes in multi-mode fiber with purity >13dB.
We report cascaded four-wave mixing in a silicon micro-ring resonator operating at 4.5 μm wavelength. Our results present an important milestone for extending optical frequency combs further into the mid-infrared range.
We demonstrate a hybrid material platform, in which a layer of crystalline silicon is placed on top of a silicon nitride on a silicon dioxide die. We also report an efficient interlayer coupling structure with 0.02 dB insertion loss. Using this hybrid platform, high-Q resonators are demonstrated.
We demonstrate a hybrid integrated optical phased array (OPA) based on a 2D photonic integrated circuit and 3D waveguides. The 4×4 OPA supports 4.93° horizontal and vertical beam steering near 1550 nm with 7.1-dB loss.
A high-temperature fiber optical hydrogen sensor is demonstrated. The sensor is based on single-crystal sapphire fiber coated with nanostractured Pd-doped TiO2 thin film. The sensitivity of the sensor was evaluated for hydrogen concentrations varying from 0.02 % to 3% at temperature up to 800°C.
Microresonator based optical frequency combs have the potential to greatly extend optical frequency measurements. Here we demonstrate the first self-referenced microresonator based optical comb suitable for optical frequency metrology applications.
Laser absorption is ideal for monitoring reactive systems with applications ranging from fundamental studies of combustion chemistry to control of power plant emissions. Sensor design, new schemes for sensitivity in harsh environments, and successful applications are reviewed.
By employing 25-GHz-mode-spacing electro-optics-modulator-based optical frequency comb at telecommunications wavelengths, we have successfully demonstrated that phase noise in a commercially available signal generator at 25 GHz can be dramatically reduced to less than ever before.
We report on monolithic 4×20 silicon photonic MEMS switches capable of multicast functions. The switch has small footprint (1.2×4.5mm2), low optical insertion loss (<4.0dB), fast switching (9.6μs). 1×2 and 1×4 multicasts were successfully demonstrated.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.