Abstract
Numerical investigation of a Mach-Zehnder interferometer implemented by steering self-collimated acoustic beams in a two-dimensional phononic crystal is presented. Mirrors of the interferometer are optimized by modifying the radii of the steel cylinders in water so that the working frequencies lie in a band gap. The beam splitters optimized in a similar manner ensure equal splitting of the beams. In the all-water case of host liquid, the interferometer operates unidirectionally such that transmission through only one of the two output terminals is achieved. Corresponding transmittances are 85.9% and 6.0% for the transmitting and blocked terminals, respectively. The device can be utilized in sensing variations in the weight fraction of ethanol in water in a cell on the path of one of the two split beams. Phase difference accumulated in the sample cell varies linearly with ethanol weight fraction up to 15%. Contrast ratio of the calculated transmittances can be used as a measure of ethanol content in water, as it varies as a cosine function of ethanol weight fraction.
| Original language | English |
|---|---|
| Pages (from-to) | 197-203 |
| Number of pages | 7 |
| Journal | Sensors and Actuators, B: Chemical |
| Volume | 203 |
| DOIs | |
| Publication status | Published - Nov 2014 |
| Externally published | Yes |
Keywords
- Liquid concentration sensing
- Mach-Zehnder interferometer
- Phase difference
- Phononic crystal