Characteristics of ultra-compact polymer modulators based on silicon photonic crystal ring resonators

Optoelectronic Devices and Integration III

Jiang

et al. 2010

Self Cite

We proposed a new channel drop filter (CDF) based on race-track photonic crystal ring resonator (PCRR) composed of square-lattice cylindrical silicon rods in air. Two representative scenarios, parallel and perpendicular, related to the direction of race track and bus channel waveguide, are comparably studied by using 2D finite-difference time-domain technique. A good set of parameters with adequate modal spacing can be determined by adjusting the amount and size of scatterers. By optimizing the relationship among surrounding periods, race-track ring size and coupling strength, more than 150 spectral quality factor and 93.9% dropped efficiency can be achieved at 1370-nm channel for one single race-track PCRR. These findings enhance and enrich the PCRRs as an alternative to current micro-ring resonators for ultra-compact WDM components and high density photonic integration.

Section: Introductionmentioning

confidence: 99%

Ultracompact channel filters based on race-track photonic crystal ring resonators

Optoelectronic Devices and Integration III

Jiang

et al. 2010

Self Cite

“…Additionally, they are also highly sensitive to the surface roughness and the nanoscale gap between the ring resonator and the bus waveguide, which creates another challenge in manufacturing [3]. Recently, photonic crystal ring resonators (PCRRs) have been proposed to overcome the aforementioned technical bottleneck [4,5].…”

Section: Introductionmentioning

confidence: 99%

Optical Channel Drop Filters based on 45° Photonic Crystal Ring Resonators

Bai

Asia Communications and Photonics Conference and Exhibition

Niu

et al. 2009

Self Cite

“…For the 1550 nm communication window, a is set as 685 nm. Based on the concept of effective ring radius R eff [13] , R eff in Fig.1(a) is / 32 2 a , about 2.186 m. For comparison, a conventional 5 5 PCRR whose R eff is / 36 2 a , about 2.318 m is also considered here. 8 same additional Si scatterers labeled as S in Fig.1(a) are introduced in the center of their four nearest-neighbor rods to improve the spectral selectivity and obtain a very high dropped efficiency [12] .…”

mentioning

confidence: 99%

“…Additionally, the performance of WGM ring resonators is also highly sensitive to the surface roughness and the nano-gap between the ring resonator and the bus waveguide. On the other hand, various types of photonic crystal ringshaped waveguide resonators [7][8][9][10][11][12][13] have been reported. However, the hybrid configuration [7] can , t further reduce the size of resonator.…”

mentioning

confidence: 99%

“…In the PC self-collimated loop structure [10,11] , self-collimation can only exist in special propagation directions and within a certain self-collimated frequency range. PCRRs [12,13] have attracted great interest [14][15][16] for their scalable ring sizes and flexible mode coupling configurations. Potentially, PCRRs present a solution to overcome the scaling obstacle of traditional WGM resonators.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Characteristics of 45° photonic crystal ring resonators based on square-lattice silicon rods

Bai

Chen

et al. 2010

Optoelectron. Lett.

A new photonic crystal ring resonator (PCRR) configuration is provided based on two-dimensional (2D) square lattice photonic crystal (PC) silicon rods. The ring is formed by removing the line defect along M direction instead of conventional X direction. Its spectral information including transmission intensity, dropped efficiency and quality factor affected by different physical parameters and the cascaded engineering including parallel and serial configurations are numerically analyzed with 2D finite-difference time-domain (FDTD) technique. The spectral quality factor of more than 830 and dropped efficiency of 90% at 1550 nm channel can be obtained with a less than 2.2 m ring radius.Ring resonators, owing to their high spectral selectivity and wide free spectral range (FSR), have attracted growing attention in device applications [1][2][3][4][5] . Ring resonators have been successfully demonstrated in a variety of materials including optical fibers [1,6] , low index contrast dielectric materials (material index contrast n < 2, e.g., polymer [2] ), and high index contrast semiconductor materials ( n 2, e.g., SOI [3] ). Typically, systems based on the traditional optical fiber ring technology are bulky and incompatible with photonic integration. One of the most promising designs is the planarwaveguide-based integrated micro-ring resonator, also called the whispering-gallery-mode (WGM) micro-resonator. However, for WGM ring resonators, limited by the total internal reflection (TIR) confinement principle, their propagation losses increase exponentially with the reduction of ring radii. This presents a problem for scaling. In practice a lower limit is set on the ring radius of a few micrometers (e.g. 3 m). Additionally, the performance of WGM ring resonators is also highly sensitive to the surface roughness and the nano-gap between the ring resonator and the bus waveguide. On the other hand, various types of photonic crystal ringshaped waveguide resonators [7][8][9][10][11][12][13] have been reported. However, the hybrid configuration [7] can , t further reduce the size of resonator. The ring miniaturization of PC directional loop [8,9] is limited by the required long coupling length. In the PC self-collimated loop structure [10,11] , self-collimation can only exist in special propagation directions and within a certain self-collimated frequency range. PCRRs [12,13] have attracted great interest [14][15][16] for their scalable ring sizes and flexible mode coupling configurations. Potentially, PCRRs present a solution to overcome the scaling obstacle of traditional WGM resonators.Here we present a new configuration of PCRR based on the square-lattice PC pattern by forming the ring resonator along M direction (removing one line of rods along M direction) instead of previously demonstrated X direction. The performance of new PCRR is investigated by using 2D FDTD.The schematic diagram of proposed 45° PCRR is shown in Fig.1(a), which is a square lattice with silicon rods in air (refractive index n Si =3.48 and n air =1). ...