Broadband air-clad LP02 mode converter using a tapered mode transition

Opt Lett. 2022 Jan 1;47(1):38-41. doi: 10.1364/OL.446055.

Abstract

Higher-order mode converters that work over a broad wavelength range are needed for various applications. A new, to the best of our knowledge, simple and cost-effective LP02 mode converter is fabricated by tapering a bundle of single-mode fibers. The device excites the LP02 mode in a four-mode step index fiber with a mode purity higher than 10 dB. The polarization-dependent cross talk of the device is measured using the S2 technique. The LP02 mode selectivity of the device is measured over the entire C and L bands by selectively launching different modes into the device using a spatial light modulator.