Single-mode rib optical waveguides on SOG/SU-8 polymer and integrated Mach-Zehnder for designing thermal sensors

Abstract

International audienceThis paper presents a successful design, realization,and characterization of single-mode rib optical waveguides on SOG/SU-8 polymers in order to highlight a new approach to designing heat sensors. The basic principle of this new thermal-sensing method relies on the differential thermal behavior regarding both acting arms of a micro Mach-Zehnder Interferometer(MZI). First, two families of single-mode straight rib waveguides composed of SOG/SU-8 polymers are analyzed. Hence, optical losses for TE00 and TM00 optical modes for structures on Si/SiO2/SU-8 have been estimated respectively as 1,36 plusmn 0,02 and 2,01plusmn0,02 dBmiddotcm-1, while the second one composed of Si/SiO2 /SOG/SU-8 presented losses of 2,33 plusmn 0,02 and 2,95plusmn0,02 dBmiddotcm-1. Then, owing to modeling results, an experimental sensor is realized as an integrated device made up of SU-8 polymer mounted on a standard silicon wafer. When subjected to a radiant source, as a laser light (980 nm) is injected across the cleaved input face of the MZI, the significant change of output signal allows us to consider a new approach to measuring radiant heat flowrate. Experimental results are given regarding the obtained phase shift against the subjected thermal power. According to the modeling results, one can expect new highly sensitive devices to be developed in the next coming years, with advantageous prospective industrial application

Development and fabrication of an optimized thermo-electro-optic device using a Mach–Zehnder interferometer

“…Furthermore, since the etching is realized by the front-side of the silicon wafer, it was possible to reduce the KOH silicon substrate etching time (approximately 70 min), when compared to other results [9,14] where the etching is made from the back-side.…”

Spin coating and plasma process for 2.5D integrated photonics on multilayer polymers

“…A laser source operating at 670 nm and micromanipulators are used to assess and confirm the single-mode characteristic of the structure. Then, with such integrated photonic devices detailed in references [7,8,15,16], single mode TE 00 (TM 00 ) propagation has been achieved first into the rib waveguide with a proper confinement allowing an adequate propagation. At last, a TE 00 (TM 00 ) polarized whispering gallery mode has been excited into a micro-disk presenting a single characteristic propagation mode that is strongly localized near the circumference of the disk as depicted in Fig.…”

“…Within the past two decades, the interest in micro-opto-electromechanical systems (MOEMS) has expanded with the development of a number of devices in the fields of telecommunications [1][2][3] and sensors [4][5][6][7][8][9][10][11][12]. Introducing polymers in MOEMS fabrication presents significant advantages, such as large volume and low-cost production.…”

“…Focusing on applications with sundry micro-optical elements, the polymer SU8 [13] (biphenol A ether glycidyl polymer manufactured by MicroChem Corp.) shows a high transparency above 400 nm and exhibits low propagation losses close to 1 dB cm − 1 as commonly used in waveguiding [14][15][16]. Consequently, SU8 comes up as one of the most attractive polymers to develop low-cost versatile MOEMS [6][7][8][9][10][11][12] especially based on planar 2D-photonics like Mach-Zehnder (MZ) structures achieved with classical UV-lithography process [7,8] or 2D-Micro-Resonators (MR) [17,18] realized with specific e-beam lithography. Parallel to SU8, siloxane spin-on-glass (SOG) [19] and polymeric silane PS233 [20], manufactured respectively by Honeywell International Inc. and Ugarit-Chimie Ltd. present both good transparency and low absorption at visible and telecommunication wavelengths and are of noticeable interest as lower cladding layer materials in the MZ-and MR-2D-planar photonics devices.…”

Transferable Integrated Optical SU8 Devices: From Micronic Waveguides to 1D-Nanostructures

“…Additional steps involving plasma treatments have been demonstrated for improving these propagation losses [5]. More complex passive SU8 structures have been realized, such as interferometric structures for thermal, pressure or biological sensors [6][7][8], microresonators [9][10][11], or optical accelerometers [12]. Regarding active SU8-based structures, the main strategy deals with the dispersion of dyes in the SU8 matrix leading to amplified emission of rare-earths [13] or rhodamine [14].…”