ABSTRACT
In this paper, a simplified model of silicon phase modulators is presented that enables favorable accuracy together with a substantial reduction in computational effort and without the requirement of semiconductor TCAD device simulation software. This permits fast optimization of the different parameters of a modulator. The model was successfully implemented in Phoenix Optodesigner optical software allowing the optimization of silicon phase shifters for different applications. Moreover, this model presents a great potential for the simulation of modulators based on PN interdigitated junctions, which normally require complex and time consuming 3D simulations. Simulation time was reduced by a factor of 6 for the lateral PN junction based modulator, and two orders of magnitude reduction was obtained for interdigitated PN junctions based modulators.
ABSTRACT
Protein detection and characterization based on Broad-band Mach-Zehnder Interferometry is analytically outlined and demonstrated through a monolithic silicon microphotonic transducer. Arrays of silicon light emitting diodes and monomodal silicon nitride waveguides forming Mach-Zehnder interferometers were integrated on a silicon chip. Broad-band light enters the interferometers and exits sinusoidally modulated with two distinct spectral frequencies characteristic of the two polarizations. Deconvolution in the Fourier transform domain makes possible the separation of the two polarizations and the simultaneous monitoring of the TE and the TM signals. The dual polarization analysis over a broad spectral band makes possible the refractive index calculation of the binding adlayers as well as the distinction of effective medium changes into cover medium or adlayer ones. At the same time, multi-analyte detection at concentrations in the pM range is demonstrated.
Subject(s)
Biosensing Techniques , Interferometry/methods , Optics and Photonics/methods , Algorithms , Models, Theoretical , Proteins/chemistry , Sensitivity and SpecificityABSTRACT
Broad-band Mach-Zehnder interferometry is analytically described and experimentally demonstrated as an analytical tool capable of high accuracy refractive index measurements over a wide spectral range. Suitable photonic engineering of the interferometer sensing and reference waveguides result in sinusoidal TE and TM spectra with substantially different eigen-frequencies. This allows for the instantaneous deconvolution of multiplexed polarizations and enables large spectral shifts and noise reduction through filtering in the Fourier Transform domain. Due to enhanced sensitivity, optical systems can be designed that employ portable spectrum analyzers with nm range resolution without compromising the sensor analytical capability. Practical detection limits in the 10(-6)-10(-7) RIU range are achievable, including temperature effects. Finally, a proof of concept device is realized on a silicon microphotonic chip that monolithically integrates broad-band light sources and single mode silicon nitride waveguides. Refractive index detection limits rivaling that of ring resonators with externally coupled laser sources are demonstrated. Sensitivities of 20 µm/RIU and spectral shifts in the tens of a pm are obtained.
ABSTRACT
Integrated Al(2)O(3):Er(3+) channel waveguide ring lasers were realized on thermally oxidized silicon substrates. High pump power coupling into and low laser output power coupling from the ring is achieved in a straightforward design. Output powers of up to 9.5 microW and slope efficiencies of up to 0.11% were measured while lasing was observed for a threshold diode-pump power as low as 6.4 mW for ring lasers with cavity lengths varying from 2.0 to 5.5 cm. Wavelength selection in the range 1530-1557 nm was demonstrated by varying the length of the output coupler from the ring.
