Abstract Free-spectral-range (FSR)-free optical filters have always been a critical challenge for photonic integrated circuits. A high-performance FSR-free filter is highly desired communication, spectroscopy, and sensing applications. Despite significant progress in filters, the with tunable narrow-band, high out-of-band rejection, large fabrication tolerance has rarely demonstrated. In this p...

Press-induced long-period fiber gratings exhibiting strong core-to-cladding mode coupling were formed in photonic crystal fiber. Only one resonance peak was observed over a 600 nm spectral range and the resonant wavelength was tuned over the whole range by tilting a groove plate before pressing the fiber. The resonant wavelength decreased with increasing periodicity of the grating, which was op...

This paper reviews our recent activities on nanophotonics based on a photonic crystal (PC)/quantum dot (QD)-combined structure for an all-optical device and a metal/semiconductor composite structure using surface plasmon (SP) and negative refractive index material (NIM). The former structure contributes to an ultrafast signal processing component by virtue of new PC design and QD selective-area...

This paper demonstrated a multi-channel Wavelength-Division-Multiplexing (WDM) system using photonic crystal structures. The system consists of a waveguide that realized by a defect row of photonic crystal and high Q-value micro-cavities. Two-Dimension (2-D) Finite-Difference-TimeDomain (FDTD) method is performed for simulation in this paper. The results showed good ability to filter an inciden...

We propose a memorable and electrically tunable photonic device by infiltrating a dual-mode chiral-doped dual-frequency liquid crystal (LC) as the central defect layer in a one-dimensional photonic crystal (PC). According to the transmission properties of this structure, the wavelength tunability of defect modes is obtained by manipulating the LC layer in the dynamic mode due to the electricall...

A self-contained coupled-mode theory for the coupled two asymmetric photonic crystal waveguides (PCWs) is presented. The first-order coupled-mode equations are derived under a weak coupling assumption. The coupling coefficients are obtained systematically by a matrix calculus using the modal solutions of each PCW in isolation. The coupled-mode equations are solved for contra-directional couplin...

Polymers have appealing optical, biochemical, and mechanical qualities, including broadband transparency, ease of functionalization, and biocompatibility. However, their low refractive indices have precluded wavelength-scale optical confinement and nanophotonic applications in polymers. Here, we introduce a suspended polymer photonic crystal (SPPC) architecture that enables the implementation o...

A metallic photonic crystal filter has been demonstrated at terahertz frequencies, with the passband tuneable over the range 365 386 GHz. Tuning is achieved by a relative lateral shift of two metallic photonic crystal plates. Each plate comprises two orthogonal layers of gratings and integral mounting lugs. The plates are micromachined from silicon wafers then coated in gold to provide metallic...

Microphotonic structures that strongly confine light, such as photonic crystals and micron-sized resonators, have unique characteristics that could radically advance technology. However, such devices cannot be used in most applications because of their inherent polarization sensitivity; they respond differently to light polarized along different axes7–9. To take advantage of the distinctive pro...

In this paper, a new design of demultiplexer based on two-dimensional photonic crystal ringresonator is proposed. The structure is made of a hexagonal lattice of silicon rods with therefractive index 3.46 in coefficient of air with refractive index 1. The transmission efficiencyand Quality factor for our proposed demultiplexer, respectively, are more than 65% and1600. The normalized transmissio...