We report a silicon photonic dual-gas sensor based on a wavelength-multiplexed microring resonator array for simultaneous detection of H2 and CO2 gases. The sensor uses Pd as the sensing layer for H2 ...gas and a novel functional material based on the Polyhexamethylene Biguanide (PHMB) polymer for CO2 gas sensing. Gas sensing experiments showed that the PHMB-functionalized microring exhibited high sensitivity to CO2 gas and excellent selectivity against H2. However, the Pd-functionalized microring was found to exhibit sensitivity to both H2 and CO2 gases, rendering it ineffective for detecting H2 in a gas mixture containing CO2. We show that the dual-gas sensing scheme can allow for accurate measurement of H2 concentration in the presence of CO2 by accounting for the cross-sensitivity of Pd to the latter.
We report a silicon photonic dual-gas sensor based on a wavelength-multiplexed microring resonator array for simultaneous detection of H
and CO
gases. The sensor uses Pd as the sensing layer for H
...gas and a novel functional material based on the Polyhexamethylene Biguanide (PHMB) polymer for CO
gas sensing. Gas sensing experiments showed that the PHMB-functionalized microring exhibited high sensitivity to CO
gas and excellent selectivity against H
. However, the Pd-functionalized microring was found to exhibit sensitivity to both H
and CO
gases, rendering it ineffective for detecting H
in a gas mixture containing CO
. We show that the dual-gas sensing scheme can allow for accurate measurement of H
concentration in the presence of CO
by accounting for the cross-sensitivity of Pd to the latter.
There is little literature characterizing the temperature-dependent thermo-optic coefficient (TOC) for low pressure chemical vapor deposition (LPCVD) silicon nitride or plasma enhanced chemical vapor ...deposition (PECVD) silicon dioxide at temperatures above 300 K. In this study, we characterize these material TOC's from approximately 300-460 K, yielding values of (2.51 ± 0.08) · 10
K
for silicon nitride and (5.67 ± 0.53) · 10
K
for silicon oxide at room temperature (300 K). We use a simplified experimental setup and apply an analytical technique to account for thermal expansion during the extraction process. We also show that the waveguide geometry and method used to determine the resonant wavelength have a substantial impact on the precision of our results, a fact which can be used to improve the precision of numerous ring resonator index sensing experiments.
Harnessing the full complexity of optical fields requires the complete control of all degrees of freedom within a region of space and time—an open goal for present-day spatial light modulators, ...active metasurfaces and optical phased arrays. Here, we resolve this challenge with a programmable photonic crystal cavity array enabled by four key advances: (1) near-unity vertical coupling to high-finesse microcavities through inverse design; (2) scalable fabrication by optimized 300 mm full-wafer processing; (3) picometre-precision resonance alignment using automated, closed-loop ‘holographic trimming’; and (4) out-of-plane cavity control via a high-speed μLED array. Combining each, we demonstrate the near-complete spatiotemporal control of a 64 resonator, two-dimensional spatial light modulator with nanosecond- and femtojoule-order switching. Simultaneously operating wavelength-scale modes near the space–bandwidth and time–bandwidth limits, this work opens a new regime of programmability at the fundamental limits of multimode optical control.Panuski et al. demonstrate a programmable photonic crystal cavity array, enabling the spatiotemporal control of a 64 resonator, two-dimensional spatial light modulator with nanosecond- and femtojoule-order switching.
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GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZAGLJ
A successful design, fabrication and test of silicon photonic circuits requires design tools, process design kits (PDKs), foundries for fabrication, and test facilities. This paper describes the ...complete design flow of photonic circuits using rapid-prototyping multiproject wafer foundry processes available in the SiEPIC program. The focus of this paper is on rapid prototyping based on electron beam lithography as an alternative and complementary to what is available via deep-UV lithography-based foundries. We describe in detail the PDK and the use of open-source and commercial tools for the design of optical filters, sensors, neuromorphic photonic processors, optical switches, and discuss test and packaging approaches for these designs. We demonstrate that a "germanium less" process can be used to build small systems featuring photoconductive detectors, electronics, and phase shifters.
Subwavelength grating (SWG) metamaterial waveguides and ring resonators on a silicon nitride platform are proposed and demonstrated. The SWG waveguide is engineered such that a large overlap of 53% ...of the Bloch mode with the top cladding material is achieved, demonstrating excellent potential for applications in evanescent field sensing and light amplification. The devices, which have critical dimensions greater than 100 nm, are fabricated using a commercial rapid turn‐around silicon nitride prototyping foundry process using electron beam lithography. Experimental characterization of the fabricated device reveals excellent ring resonator internal quality factor (2.11 × 105) and low propagation loss (≈1.5 dB cm−1) in the C‐band, a significant improvement of both parameters compared to silicon‐based SWG ring resonators. These results demonstrate the promising prospects of SWG metamaterial structures for silicon nitride based photonic integrated circuits.
Silicon nitride‐based subwavelength grating metamaterial waveguides and ring resonators are demonstrated. The devices are fabricated using a commercial rapid prototyping foundry process and exhibit an internal quality factor of 2.11 × 105 and propagation loss of ≈1.5 dB cm−1 in the C‐band. This opens promising prospects for subwavelength grating metamaterial engineering in silicon nitride integrated photonic devices.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
We report a simple and robust method for fabricating graphene-on-silicon waveguides on a silicon-on-insulator (SOI) chip. The waveguide consists of a silicon core covered by a graphene layer whose ...width exactly conforms with the width of the silicon core and whose length can be precisely controlled. Raman spectroscopy showed that the graphene layer retained its high quality after processing. Transmission measurements of fabricated graphene-on-silicon waveguides showed polarizationdependent propagation losses of 0.03 dB/μm for the transverseelectric (TE) mode and 0.07 dB/μm for the transverse-magnetic (TM) mode, in excellent agreement with theoretical simulations.
We report the design and fabrication of hybrid plasmonic waveguides based on the Au/SiO 2 /SU-8 material system. Monolithic integration of these devices with dielectric SU-8 waveguides on the same ...chip enabled efficient and broadband coupling between photonic and plasmonic devices to be achieved. Compact hybrid plasmonic microring resonators were also demonstrated with high intrinsic Q -factors close to 300.
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