All polymer asymmetric Mach–Zehnder interferometer waveguide sensor by imprinting bonding and laser polishing

Abstract

We present an all polymer asymmetric Mach-Zehnder interferometer (AMZI) waveguide sensor based on imprinting bonding and laser polishing method. The fabrication methods are compatible with high accuracy waveguide sensing structure. The rectangle waveguide structure of this sensor has three sensing surfaces contacting the test media, and its sensing accuracy can be increased 5 times compared with that of one surface sensing structure. An AMZI device structure is designed. The single mode condition, the length of the sensing arm, and the length deviation between the sensing arm and the reference arm are optimized. The length deviation is optimized to be 19.8 µm in a refractive index range between 1.470 and 1.545. We fabricate the AMZI waveguide by lithography and wet etching method. The imprinting bonding and laser polishing method is proposed and investigated. The insertion loss is between −80.36 dB and −10.63 dB. The average and linear sensitivity are 768.1 dB/RIU and 548.95 dB/RIU, respectively. And the average and linear detection resolution of the sensor are 1.30×10 −6 RIU (RIU: refractive index unit) and 1.82×10 −5 RIU, respectively. This sensor has a fast and cost-effective fabrication process which can be used in the cases of requiring portability and disposability.

Evanescent Field Controllable MZ Sensor via Femtosecond Laser Processing and Mechanic Polishing

“…The middle part of an MZ interferometer is considered a phase delay line because the only parameter of interest is the phase difference between the two arms [23]. We can set the phase change of the contrast arm as 0 and the phase change of the sensing arm as ϕ.…”

Coupled resonator-induced transparency on a three-ring resonator

“…Since the resonator produces optical power loss, some of the power of loss is converted into heat energy, and the temperature of the resonator is raised, thus affecting the refractive index of the waveguide medium. [25] This change will cause the drift of the resonant frequency, which will change the performance of the device. In order to obtain the sensitivity of the cascaded ring resonator to the temperature, a temperature tuning experiment was carried out on the resonator of the threering cascade structure.…”

Highly Sensitive Liquid M-Z Waveguide Sensor Based on Polymer Suspended Slot Waveguide Structure

“…Regarding the device structure, the device structures of existing optical waveguide sensors are mainly microdisk resonators [ 21 ], microring resonators [ 22 ], MZI [ 23 , 24 , 25 , 26 ], and Young’s interferometer [ 27 ]. Ring resonators are compact and easy to multiplex, but an expensive and bulky high-resolution wavelength-tunable laser is often required to operate the silicon microring resonator and its detection limit is ultimately restricted by the laser resolution [ 28 ].…”