Andrzej Kazmierczak

On-chip temperature compensation in an integrated slot-waveguide ring resonator refractive index sensor array

We present an experimental study of an integrated slot-waveguide refractive index sensor array fabricated in silicon nitride on silica. We study the temperature dependence of the slot-waveguide ring resonator sensors and find that they show a low temperature dependence of -16.6 pm/K, while at the same time a large refractive index sensitivity of 240 nm per refractive index unit. Furthermore, by using on-chip temperature referencing, a differential temperature sensitivity of only 0.3 pm/K is obtained, without individual sensor calibration. This low value indicates good sensor-to-sensor repeatability, thus enabling use in highly parallel chemical assays. We demonstrate refractive index measurements during temperature drift and show a detection limit of 8.8 x 10-6 refractive index units in a 7 K temperature operating window, without external temperature control. Finally, we suggest the possibility of athermal slot-waveguide sensor design.

Heterogeneous integration of electrically driven microdisk based laser sources for optical interconnects and photonic ICs

A new approach for an electrically driven microlaser based on a microdisk transferred onto Silicon is proposed. The structure is based on a quaternary InGaAsP p-i-n junction including three InAsP quantum wells, on a thin membrane transferred onto silicon by molecular bonding. A p++/n++ tunnel junction is used as the p-type contact. The technological procedure is described and first experimental results show a laser emission in pulsed regime at room temperature, with a threshold current near 1.5 mA.

High efficiency silicon nitride surface grating couplers

High efficiency surface grating couplers for silicon nitride waveguides have been designed, fabricated, and characterized. Coupling efficiencies exceeding 60 % are reported at a wavelength of 1.31 mum, as well as angular and wavelength -3 dB tolerances of 4 degrees and 50 nm, respectively. When the wavelength is increased from 1310 nm to 1450 nm the coupling efficiency progressively decreases but remains above 20 % at 1450 nm. The influence of the duty ratio of the grating has also been investigated: maximum coupling efficiency was obtained at 50 % duty ratio.

Design, simulation, and characterization of a passive optical add-drop filter in silicon-on-insulator technology

We present a passive novel optical add-drop filter incorporating microdisk resonators, in complementary metal-oxide-semiconductor compatible silicon-on-insulator technology, which enables a simple layout of complex optical networks-on-chip. The measured properties of the fabricated devices are in agreement with theory, established using the time-domain coupled mode theory and finite-difference time-domain simulations.

Highly Integrated Optical 4

In this paper, we present the design, fabrication, and characterization of a highly integrated optical 4 x 4 crossbar based on microring resonator add-drop filters. The designed crossbar structure, as small as 50 mum x 50 mum, has been fabricated in CMOS compatible silicon on insulator technology. Finally, experimental results proving the proper operation of the fabricated crossbar structures are discussed.

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A two-dimensional photonic crystal channel-drop filter is proposed. This device has two high group velocity waveguides that are selectively coupled by a single, low group velocity intermediate waveguide section. It exhibits computed quality factors as high as 1300, and directional dropping efficiencies as high as 90%.

4 Crossbar in Silicon-on-Insulator Technology

We present an efficient and highly alignment-tolerant light coupling and distribution system for a multichannel Si3N4/SiO2 single-mode photonics sensing chip. The design of the input and output couplers and the distribution splitters is discussed. Examples of multichannel data obtained with the system are given.

Directional channel-drop filter based on a slow Bloch mode photonic crystal waveguide section

The experimental demonstration of a high efficiency silicon nitride grating coupler is reported for wavelengths from lambda = 1.25 to 1.45 mum for TE polarization. At the resonant angle, a coupling efficiency higher than 60% has been measured.

Light coupling and distribution for Si3N4∕SiO2 integrated multichannel single-mode sensing system

We present a compact passive optical add-drop filter which incorporates two microring resonators and a waveguide intersection in silicon-on-insulator (SOI) technology. Such a filter is a key element for designing simple layouts of highly integrated complex optical networks-on-chip. The filter occupies an area smaller than 10μm×10μm and exhibits relatively high quality factors (up to 4000) and efficient signal dropping capabilities. In the present work, the influence of filter parameters such as the microring-resonators radii and the coupling section shape are analyzed theoretically and experimentally

A high efficiency silicon nitride grating coupler

In this paper, a band-stop radiation filter based upon a planar photonic crystal single-defect micro-cavity is studied. The micro-cavity is located within a photonic crystal region and fed by a ridge waveguide. Because the micro-cavity structure is bounded on one side by a limited number of crystal rows, there is strong radiation, at resonance, into the surrounding 2D slab (i.e., the region that is free from the photonic crystal). The antenna radiation pattern of this micro-cavity can be substantially directional and is strongly dependent upon the cavity resonant wavelength, giving the possibility for this device to act as a directional radiation filter.The theoretical analysis of this device is performed by using 2D Finite-Difference Time-Domain (FDTD) methods, while the device is fabricated in an InP epi-layered structure. Initial characterization results are also presented for this single-defect radiation filter.