Enhancing the impedance matched bandwidth of bottle microresonator signal processing devices

Light pulses entering an elongated bottle microresonator (BMR) from a transversely oriented input–output waveguide (microfiber) slowly propagate along the BMR length and bounce between turning points at its constricting edges. To avoid insertion losses processing errors, pulse should completely transfer into and, after being processed, return back waveguide. For this purpose, be impedance matched bandwidth. Here we show how to enhance bandwidth by optimization of effective radius variation in small vicinity