We describe a method that enables free-standing whispering-gallery-mode microresonators, and report spectral tuning of photonic molecules formed by coupled free and on-chip resonators with different geometries and materials. We study direct coupling via evanescent fields of free silica microtoroids and microspheres with on-chip polymer coated silica microtoroids. We demonstrate thermal tuning o...

This paper describes the modeling and design of a novel Electro-Absorption Modulator (EAM) based on a Multi-Mode Interference (MMI) waveguide that utilizes the combination of optical absorption and mode interference effects to improve the extinction ratio of the EAM. In addition, modeling and design of an Evanescent Coupler based EAM with improved performance based on a similar dual extinction ...

We demonstrate a wavelength-tunable, passively mode-locked erbium-doped fiber laser based on graphene and chirped fiber Bragg grating. The saturable absorber used to enable passive mode-locking in the fiber laser is a section of microfiber covered by graphene film, which allows light-graphene interaction via the evanescent field of the microfiber. The wavelength of the laser can be continuously...

We have produced high transmission sub-wavelength tapered optical fibers for the purpose of whispering gallery mode coupling in fused silica microcavities at 780 nm. A detailed analysis of the fiber transmittance evolution during tapering is demonstrated to reflect precisely the mode coupling and cutoff in the fiber. This allows to control the final size, the number of guided modes and their ef...

The efficiency of evanescent coupling between a silica optical fiber taper and a silicon photonic crystal waveguide is studied. A high-reflectivity mirror on the end of the photonic crystal waveguide is used to recollect, in the backward-propagating fiber mode, the optical power that is initially coupled into the photonic crystal waveguide. An outcoupled power in the backward-propagating fiber ...

Passive harmonic mode-locking in soliton fiber laser is presented with excellent noise characteristics by employing a single-walled carbon nanotubes saturable absorber designed to interact with evanescent wave of the laser field. The 34(th) harmonic mode-locking pulses at 943.16 MHz repetition rate were stably generated with 18 mW output power, >50 dB side-mode suppression and -140 dB/Hz relati...

Two-dimensional finite-difference time-domain (FDTD) method has been performed to numerically investigate the transmission through a one-dimension cupped surface metallic grating structure. The concept of coupling of optical modes in the notches and main slits, introduced by Crouse and Keshavareddy [1], is examined further in our work. Unexpected phenomenon is shown that even horizontal surface...

The mode spectrum of a 3.8-cm-diameter fused-silica sphere has been studied in the vicinity of 1.06 microm. A single-frequency Nd:YAG laser was used to excite whispering gallery modes by means of evanescent wave coupling. The spectrum is in excellent agreement with predictions from Mie theory.