Cellular-dimension picoliter-volume index microsensing using micro-abrupt-tapered fiber Mach-Zehnder interferometers

A Review of Microfiber and Nanofiber Based Optical Sensors

“…Typical fabricated samples were of 35-56 µm thinned fiber diameter, 30-49 µm taper diameter and 372 µm taper length. Another double-taper based interferometric sensor was reported by Chen et al [95], with MNF diameters of 58.5 µm and 53.7 µm, and lengths of 2.4 mm and 2.2 mm. The RI sensitivity was as high as 4000 nm/RIU at the operating wavelength of 1.61 µm and n = 1.33.…”

In-line high sensitivity tapered-fiber Mach-Zehnder interferometer for aerospace sensing applications

“…In aerospace photonic applications, fiber sensors with compact size, low cost, simple structure, high sensitivity, high environment stability, and multiple measurands are highly appreciated [1][2][3][4]. Usually, fiber-optic sensors are based on fiber Bragg gratings, gyroscopes, long period gratings, abrupttapered-fiber Michelson interferometers (MIs) and MachZehnder interferometers (MZIs).…”

“…By varying the optical path length difference (OPLD) between the core and cladding modes in the phase shifter, the induced phase delay can be tuned to change the interfered wavelengths as well as the extinction ratios. More recently, miniaturized and integrated fiber components based on two abrupt tapers in a single fiber have been demonstrated to detect the index variations from an extremely low liquid volume [2] in a simple and cost-effective device structure. The abrupt-tapered MachZehnder interferometer (AT-MZI) is simple, high-sensitive, and cost-effective to be a high efficiency fiber sensor for aerospace sensing applications such as vibration, inclination, torsion, wind pressure and speed.…”

Interferometric Interrogation of the Inclination and Displacement of Tapered Fiber Mach-Zehnder Interferometers

“…In our experience, a waist diameter of around 40-50 μm was found to be the best parameter for the AT-MZI to have the lowest optical losses and best extinction ratios below 5 dB using EYDF. The optical losses can be further reduced to less than 2 dB [23] if the cladding diameter at the phase shifter is thinned down to be around 28 μm. Nevertheless, the extinction ratios will be also degraded [23].…”

“…The optical losses can be further reduced to less than 2 dB [23] if the cladding diameter at the phase shifter is thinned down to be around 28 μm. Nevertheless, the extinction ratios will be also degraded [23]. Based on these observations, it reflects that not all of the excited cladding modes will participate in the interferences at the second abrupt taper.…”