Research of high speed optical switch based on compound semiconductor

Abstract

High-speed optical switch and its array are the crucial components of all-optical switching system. This paper presents the analytical model of a total-internal-reflection (TIR) optical switch. By employing the carrier injection effect in GaAs and the GaAs/AlGaAs double heterojunction structure, the X-junction TIR switch and the Mach-Zehnder interference (MZI) switch are demonstrated at 1.55 μm. The measured results show that the extinction ratio of both switches exceeds 20 dB. The switching speed reaches the scale of 10 ns.optical switch, total internal reflection, multimode interference, carrier injection Optical fiber communication technology has become the backbone of modern communication network, and formed enormous applications. As a key component of optical fiber communication system, optical switch and its array have been the focus of research and development [1] . High-speed optical switch and its large-scale arrays are essential for optical network based on optical packet switching (OPS). By employing various physical effects and technology, many types of optical switch have been developed. Among them, apart from the most traditional mechanical optical switches, there are many commercial products, e.g. the micro electro mechanical system (MEMS) based switch, the silica or organic polymer based waveguide switch, and the liquid crystal based switch. They have good performances in extinction ratio, insertion loss, polarization dependence and integration. However, most of them have a low switching speed, a magnitude of milliseconds (ms) typically. OPS based network requires that the switching speed reaches a magnitude of nanoseconds (ns), thus the high-speed optical switch and its arrays are very attractive.Compound semiconductor materials are used widely for high-speed microelectronic integrated devices. Besides, they are important material for optoelectronic devices and high-speed optical waveguide devices. Compound semiconductor is a promising platform for the optical and electronic integrated circuits (OEIC). In the past 30 years, GaAs and InP-based compound semiconductor materials have played an important role in integrated optical devices [2] , especially in the development of high-speed optical switch [3] . Compound semiconductor based high optical switch mainly employ the electrooptic effect, and the carrier injection effect [4][5][6][7][8] . Because of the small electro-optic coefficient, switches based on electro-optic effect usually have large size or high driving voltage. On the other hand, similar to the electro-optic effect of LiNbO 3 , the electro-optic coefficient of compound semiconductor is polarization-dependent as well. In the communication wavelength range of 1.31-1.55 μm, the refractive index change induced by the carrier injection effect is about two orders of magnitude greater than that by the electro-optic effect, and it is very easy to obtain a refractive index change as large as

Nanosecond Bias-Free Mach–Zehnder Electro-Optic Switch Based on Dye-Doped Polymer DR1/SU-8 and Microstrip Line Electrode

“…By the virtue of less refractive index mismatch, the rise time and fall time are found to be about 14.30 ns and 14.69 ns, respectively. Therefore, this switch shows similarly fast characteristics compared to the reported carrier-injection-based EO switch; for example, the response time of the GaAs switch reported by Wang et al [21] is also about 10 ns. The inset of Figure 6 shows the dB scale of the response, and an ER within the range of 8 dB-12 dB is noticed Downloaded by [University of Chicago Library] at 06:43 17 November 2014 for the fabricated switch.…”

Normalized transfer function for characterizing conversion efficiency and harmonic distortion of all-optical sampling

“…Nonlinearity of all-optical sampling is very critical to the resolution of all-optical analog-to-digital conversion [1][2][3], and distortion analysis is needed to achieve a good sampling performance. In most cases, conversion efficiency and harmonic distortion are introduced to characterize the nonlinearity and optimize the sampling performance [4,5].…”

Ballistic transport in nanoscale self-switching devices

“…During the last two decades, the dimensions of compound semiconductor devices have become smaller. Electronic devices at micrometer and nanometer scale have attracted increasing attention [1][2][3]. In 2003, using an asymmetric structure, Song et al designed a novel device with diodelike I-V characteristics, which was called a self-switching device (SSD) [4].…”