This paper presents the design of a 1536 x 1536 pixel silicon backplane for dynamic holography in an all-optical 64 x 64 switch.
Each pixel consists of two 6T-SRAM cells, a 4-to-1 multiplexer, and a high voltage buffer. A special driving technique using digital driving of the ITO and reflector devices has enabled the chip to control the voltage across the liquid crystal sandwich with zero DC bias. The chip has been fabricated in a 0.25 μm 2.5V/5V with a special high reflectivity top metal process. The pixel dimensions is 10.8 μm X 10.8 μm with a 0.6 μm spacing between the top metals. The total chip area is 21.9 mm X 21.7 mm. At typical driving frequencies of 10 KHz the chip consumes only 100 mW.
Optical switches are among key devices for implementation of DWDM in optical networks. There are a number of technologies available to realize optical switches, including Micro-Electro-Mechanical System (MEMS) switches, Bubble-Based Waveguide Switches, Liquid Crystal on Silicon (LCOS) Switches, Electro-Optic Switches, and Thermo-Optic Switches. Among these technologies MEMS has received particular
attention in recent years, initially using 2 dimensional (2D) switches and later progressing to 3D switches. This paper evaluates Liquid Crystal on Silicon (LCOS) as an alternative to MEMS for implementation of optical switches. The opportunities and
challenges for LCOS in optical networking are discussed. Issues related to availability of LCs, switching speeds, voltage requirements, scalability, wavelength range, packaging and crosstalk are considered.
Different from traditional data traffic, multimedia traffic has stringent requirements on quality of service (QoS). For multimedia networking, a prime concern is to ensure that there are adequate network resources to meet the QoS requirements of multimedia traffic. In order to make effective traffic and congestion control, and network management, in-service QoS monitoring and estimation (ISME) has to be employed as opposed to the conventional out-of-service monitoring and testing techniques. In this paper, an ISME scheme is proposed. Virtual buffer techniques are employed in the ISME scheme to reduce the monitoring time required to make a valid observation of QoS. Simulation using both voice traffic source model and real variable bit rate video traffic is performed. Simulation results show that the proposed scheme is able to achieve better accuracy than that in the literature. Moreover, it also requires less monitoring time than that in the literature.