Sporadic-Slot Photonic-Crystal Waveguide for All-Optical Buffers With Low-Dispersion, Distortion, and Insertion Loss

Abstract

A novel structure is studied with implanting sporadic slots inside a photonic crystal waveguide (PCW) to form sporadic-slot PCW (SSPCW) for realizing compact, all-optical buffers with lowdispersion, distortion, and attenuation (DDA). We implement the first demonstration that, to the best of our knowledge, the SSPCW works for both TE-and TM-modes all-optical buffers and slow-light waveguides. High buffer performance and wider transmission bandwidth in telecommunication band are obtained, which are guaranteed through bit rate optimization that exceeded 2 Tb/s for both TE and TM modes in ultra-low dispersion region which is 20 times greater than that required for 5G mobile communications and it is also useful for all-optical signal processing. The storage length of 1 bit is obtained as 4.5202 µm for TE mode and 6.0525 µm for TM mode. Moreover, a low relative pulse distortion of 0.0801% µm −1 along the propagation path per unit length is acquired for a 0.63 ps pulse. Besides, the attenuation coefficient of the optical power pulse between the input and output is 0.0170 dB/µm. Additionally, the deigned SSPCW is insensitive for small variations of waveguide parameters and the deviation is virtually negligible between the simulated results and that of the fabricated structures with totally acceptable tolerance below ±3 nm, which is the challenge in the fabrication process of conventional PCW and PCW-cavity.

Silicon-on-Insulator Optical Buffer Based on Magneto-Optical 1 × 3 Micro-Rings Array Coupled Sagnac Ring

“…Figure 3 gives the transmission spectra of three MOMRs with amorphous GST and crystalline GST, which were calculated by transmission Equation (8). It can be seen from the calculation results that the curves of the forward and backward transmission spectra in the MOMRs covering cGST, each have one resonance peak at the wavelength of around 1.5502 µm, and the central wavelengths are basically at the same position.…”

“…Optical buffer can be realized by slowing down the propagation speed of light and extending the length of transmission medium. Therefore, optical buffers can be divided into three categories: buffers using slow light effects [1][2][3][4]; buffers based on photonic crystal (PhC) structure [5][6][7][8], including PhC cavities [6] and slotted PhC waveguides [7]; and buffers based on optical structures, including optical fiber delay-line structure [9][10][11] and optical micro-ring resonator structure [12,13]. Recently, more and more attention has been paid to the silicon-based optical buffers for miniaturization and integration.…”

“…The PhC cavities with ultra-high Q-factors and ultra-small mode volumes can be used for the design of the optical buffers with ultrafast response speed and an extremely compact size [6]. The slotted PhC waveguide has the characteristics of compact size, high sensitivity and low coupling losses [7], which can be used in all-optical buffers with low dispersion, distortion and attenuation [8]. As a miniaturized device that can be easily integrated into microsystems, more and more ring resonators are widely used in integrated system.…”

Elongated-Hexagonal Photonic Crystal for Buffering, Sensing, and Modulation

“…They are created by opening a narrow slot or irregular air gaps as a line-defect inside a PCW. Due to the discontinuity at the interface of silicon slab with high refractive index and air gaps with low index, the electric/magnetic field in the air gaps with low index is enhanced [ 2 ], with associated optical-buffer enhancement accessible from the PCW [ 3 ]. They can be advantageously used in high-sensitivity sensors [ 4 ], optical switches [ 5 ], and high-speed electro-optical modulators [ 6 ], etc.…”

“…Optical buffer is a significant component for all-optical communication networks, processors, and optical computers in the future. The unique PCW nanostructure designed is efficient for optical buffering performances [ 3 , 8 ] because of room-temperature operation [ 9 ], masterful manipulation of the guided-mode dispersion relations with a change in subtle structure parameters, and compatibility for on-chip integration [ 10 ].…”