Fabrication and characterization of optical microfiber structures

A microfiber was fabricated using a flame brushing technique. It has a transmission loss of 0.061 dBm/mm and a diameter of 2 um and therefore suitable for use in assembling Microfiber Knot Resonator (MKR) and Microfiber Mach-Zehnder Interferometer (MMZI). The assembled MKR with 3 mm diameter produces a comb spectrum with an extinction ratio of 7.4 dB, FSR of 0.33 nm, quality factor of 20,000 and finesse of 5. The transmission spectrum of the assembled MMZI structure has an extinction ratio of 11.5 dB and FSR of 0.52 nm. A hybrid structure is also assembled, which consists of a MKR with 2 mm diameter and MMZI with 3.5 m length. The spectral response of the hybrid structure has an extinction ratio of 5 dB and FSR of 0.24 nm. These structures have many possible applications especially in sensors.