The transfer function of the microring resonator is deduced, and the effects of the normalized loss, coupling coefficient and surrounding media on the resonance performance are investigated thoroughly. Utilizing the improved fused tapering tech- nique and ingenious self-coiling coupling method, a high-quality microring resonator （radius of about 500 I.tm） with larger extinction ratio （〉10 dB） and sharper resonance is designed and fabricated by a segment of continuous sub-micrometer fiber. The microring resonator constructed in this way demonstrates extremely small connection loss with communication fiber in contrast to the planar waveguide technology.
In this paper,we present a novel ultrashort pulse shaper based on complex-modulated long-period-grating coupler（CM-LPGC）.Temporal rectangular waveform with 2-ps full width at half maximum（FWHM） is obtained by transforming the input Gaussian pulse.Tolerances of the CM-LPGC-based shaper to various non-ideal excitation conditions and fabricating errors are investigated.Results confirm that CM-LPGC is stable and suitable for optical pulse shaping operation.
We propose a novel all-optical buffer and shaper based on the adjustable power transferring characteristics of the complex-modulated long-period-grating coupler(CM-LPGC)and the multiple circulations of the self-closed fiber loop.By turning on the external optical pumps,the signals can be stored by utilizing the nonreciprocal power transferring of the CM-LPGC.When the buffer time is satisfied,the signals can be extracted discretionarily by turning off the external optical pumps.In addition,by controlling the spectral bandwidth of the CM-LPGC,the temporal rectangular pulse can be obtained by re-shaping the Gaussian input signal.
