Freddie Shing-Hong Lin

An electromagnetic MEMS 2/spl times/2 fiber optic bypass switch

A fully micromachined multi-mode 2/spl times/2 fiber optic bypass switch which is small (<1 cm/sup 3/), fast (<10 msec), and low power when compared to commercial bypass switches, has been designed, fabricated, and tested. Development of this switch is driven by the rapid growth of fiber optic networks which require small, high performance bypass switches. Electromagnetic actuation is provided in the switch by control of a current through a set of 70-turn copper coils on a spring-supported silicon plate in the presence of a fixed external magnetic field. The electromagnetically induced switch deflections are modeled and shown to agree with experimental measurements. The performance of the switch is evaluated and compared to a commercial DiCon fiber optic multi-mode, bypass switch.

Optical multiplanar VLSI interconnects based on multiplexed waveguide holograms

Optical interconnects for very large scale integration systems based on planar waveguide holograms are analyzed. The combination of low loss waveguides and multiplexed waveguide holograms allows the construction of various compact planar architectures with high interconnect density and low insertion loss. The long interaction lengths possible in planar structures result in high angular and wavelength selectivity. Holographic grating couplers and multiplexed planar holograms for 1-to-3 interconnects and 1-to-3 multiple wavelength interconnects were fabricated.

Highly parallel single-mode multiplanar holographic interconnects.

We present theoretical and experimental results of a novel highly parallel multiplanar holographic interconnect design. It combines single-mode integrated optics with highly efficient volume holography and holographic waveguide couplers. A multiple-plane optical bus was fabricated. The interconnect density and power budget of the system are presented. This new type of very-large-scale integrated interconnect can provide performance benefits for local area networks and highly parallel supercomputing systems.

High-channel-density broadband wavelength division multiplexers based on periodic grating structures

High Channel density broadband wavelength division multiplexers (WDMs) based on periodic grating structures are discussed. These so-called single-window WDMs transmit a large number (> 100) of independent wavelength channels through a single fiber and within a single fiber communications window in both singlemode and multimode fiber cases. In this paper, single-grating WDMs are analyzed in the context of the fundamental relation between channel density, crosstalk, power budget, and diffraction limited beam propagation. Also, the practical aspects of WDM-based fiber optic networks for high-speed (broadband) multimedia communication are discussed.

Thick phase hologram for optical clock distribution application on wafer scale integrated circuits

We propose the first monolithic optical clock distribution network on wafer scale integrated circuits (WSIC) . This new architecture can save real estate on VLSI chips and eliminate the packaging, alignment and interface problems of previously proposed architectures. A l-to-3 optical fan out for clock signal distribution application is demonstrated by utilizing a DCC multiplexed volume hologram on a thin quartz plate.

Electro-optic hybrid rotary joint technology for Air Force tracker system power and signal transmission applications

Current ground-based tracking systems at Air Force test and tracking ranges require transmission of a variety of signals from rotating platform to fixed control center. At the moment, the task of signal rotating-to-fixed (RTF) transmission is exclusively handled by cable wrap structures, which provide small angular range, low speed, and are inconvenient to use. To solve this problem. Physical Optics Corporation has investigated an advanced electro- optic hybrid rotary joint (EOHRJ) technology for multiple channel RTF signal transmission. The developed EOHRJ provides the following features. First, it includes a unique two-layer electrical sip ring. This ring is able to accommodate hundreds of transmission channels, including electrical power, control, feedback, and low speed data signals. Second, it uses a unique optical fiber slip ring. This ring, by incorporating electrical time division multiplexing and optical wavelength division multiplexing technologies, is able to provide multiple channel, high data rate (over GBPS), and bi-directional signal transmission. Third, the three-layer overlapped EOHRJ, meets particular military application demands and is designed to be reliable for operation in harsh environments operation, adaptive to stringent size requirements, and accommodating to electrical and mechanical interfaces of current tracker systems.

Single‐mode/multimode waveguide electro‐optic grating coupler modulator

A waveguide electro‐optic grating coupler modulator based on a single straight channel waveguide and an interdigital modulation electrode structure on an electro‐optic substrate, has been reported. Both single‐mode and multimode operations are possible. Preliminary experiments have demonstrated the modulation on a proton exchanged LiNbO3 waveguide device. Modulation performed on other electro‐optic waveguides, such as GaAs, LiTaO3, and EO polymers, are also possible.

Design of achromatic holographic grating couplers for substrate and backplane optical interconnects

Abstract Holographic backplane optical interconnects for multi-board three-dimensional packaging of electronic modules have demonstrated certain interesting features. However, the effects of laser diode wavelength shifts, caused by variations in environmental temperatures and by bias fluctuations can cause undesirable coupling alignment problems, including shifting of the coupling angle and optical spot positions. These chromatic problems are particularly serious in terms of coupling from backplane to board-level waveguide interconnect networks. To solve these problems, an achromatization technique for holographic backplane couplers under substrate beam propagation geometry is presented in this paper.

Multiplexed holographic Fabry-Perot étalons.

We discuss a multiplexed holographic Fabry-Perot étalon that includes a multiplexed hologram in a novel holographic Fabry-Perot étalon. Two unique advantages can be achieved by using the multiplexed holographic Fabry-Perot étalon: coherently coupled fabrication of holographic Fabry-Perot mirrors significantly reduces the need to have the nearly flat surfaces typically required in conventional Fabry-Perot etalons, and the angular-wavelength multiplexing capability of a multiplexed hologram can be added to the tunable narrow-band filtering capability of Fabry-Perot étalons. Several types of multiplexed holographic Fabry-Perot étalon are experimentally demonstrated.

Dispersion effects in a single-mode holographic waveguide interconnect system.

Dispersion effects in a single-mode holographic waveguide interconnect system are analyzed, and the effect of a wavelength shift in laser diodes owing to the variation of environmental temperature are discussed. It is found that the stringent coupling-in requirement of the single-mode waveguide is the limiting factor of the optical interconnect performance. A novel waveguide grating coupler is thus introduced to eliminate this problem.