Simultaneous measurement of refraction and absorption with an integrated near-infrared Mach–Zehnder interferometer
Abstract
Most integrated evanescent-field photonic sensors measure changes in either the real part or the imaginary part of the complex refractive index of the sample, i.e., refraction or absorption. Here we propose and experimentally demonstrate a near-infrared sensor based on a silicon nitride Mach–Zehnder interferometer which provides a direct measurement of the complex refractive index. Our architecture exhibits a high sensitivity, achieving limits of detection below 2ṡ10‑6RIU for both the real and imaginary parts of the refractive index. We furthermore show that our sensor can be employed as an integrated dispersion spectrometer.
- Publication:
-
Optics Laser Technology
- Pub Date:
- October 2024
- DOI:
- 10.1016/j.optlastec.2024.111154
- arXiv:
- arXiv:2405.14328
- Bibcode:
- 2024OptLT.17711154T
- Keywords:
-
- Integrated photonics;
- Refraction sensor;
- Absorption sensor;
- Dispersion spectroscopy;
- Mach–Zehnder interferometer;
- Coherent phase detection;
- Physics - Optics;
- Physics - Applied Physics
- E-Print:
- Optics &