Cascaded Mach–Zehnder Interferometers Assembled by Submicrometer PTT Wires

A single bow-shaped Mach-Zehnder interferometer (MZI) and two-cascaded MZIs were assembled by flexible submicrometer polymer wires, which were directly drawn from poly(trimethylene terephthalate) melt. The size of the cascaded MZIs is tens to hundreds of micrometers and their path-length differences can be dynamically adjusted by micromanipulation under an optical microscope. Experimental results show that the cascaded MZIs have a large extinction ratio (25 dB) with a flat-top transmission over a wavelength range of 1.3-1.6 mum. The insertion losses of the cascaded MZIs with two and three bow-shaped MZIs are 1.1-1.8 and 1.5-2.3 dB, respectively.