1,720,997 research outputs found
Immersion graded index optics: theory, design, and prototypes
Full text linkImmersion optics enable creation of systems with improved optical concentration and coupling by taking advantage of the fact that the luminance of light is proportional to the square of the refractive index in a lossless optical system. Immersion graded index optical concentrators, that do not need to track the source, are described in terms of theory, simulations, and experiments. We introduce a generalized design guide equation which follows the Pareto function and can be used to create various immersion graded index optics depending on the application requirements of concentration, refractive index, height, and efficiency. We present glass and polymer fabrication techniques for creating broadband transparent graded index materials with large refractive index ranges, (refractive index ratio)(2) of ~2, going many fold beyond what is seen in nature or the optics industry. The prototypes demonstrate 3x optical concentration with over 90% efficiency. We report via functional prototypes that graded-index-lens concentrators perform close to the theoretical maximum limit and we introduce simple, inexpensive, design-flexible, and scalable fabrication techniques for their implementation
Tunable chromatic dispersion compensators using MEMS Gires-Tournois interferometers
No full textIn this paper, we report on a FIR (finite impulse response) dispersion compensator made using optical MEMS (micro-electro-mechanical systems) technology. An array of micromirrors is used in a Gires-Tournois (GT) interferometer to obtain the desired dispersion value of the device. This type of device had earlier been shown to function as an optical WDM interleaver/deinterleaver. The proposed device has a periodic transfer function in the frequency domain with a well-defined free spectral range (FSR). Because of the large number of channels in dense WDM systems, periodic filters are advantageous to avoid the need for unique filters for each WDM channel
Frontside-only processing of 2-D MEMS scanners for miniature dual-axis confocal microendoscopes
No full textInterference based optical MEMS filters
Full text linkIn this paper we describe tunable interference filters based on arrays of MEMS micromirrors. A simple analytical description of the height distribution of micromirrors needed to create a desired spectral response is presented, and the implications on the design and utility of MEMS interference filters are discussed. Finally we describe two practical filter implementations. The first enables continuous spectral control over relatively broad bands, and the second is designed for Wavelength-Division-Multiplexed fiber optic communication systems
Tunable wavelength multiplexer/demultiplexer using a MEMS Gires-Tournois interferometer
No full textIn this paper, we have demonstrated a 1×3 wavelength multiplexer/demultiplexer using optical MEMS technology based on a Gires-Tournois interferometer (GTI) with a tunable center wavelength. The center wavelength of each output port was continuously tunable across the free spectral range, and, the output port assignment can therefore be cyclically interchanged. These types of wavelength tunability and port reallocation offer useful functionality in various WDM systems
High-reflectivity, broadband monolithic silicon photonic crystal mirrors on two-axis MEMS scanner by transfer-printing
No full textScaling Internet routers using optics
No full textRouters built around a single-stage crossbar and a centralized scheduler do not scale, and (in practice) do not provide the throughput guarantees that network operators need to make efficient use of their expensive long-haul links. In this paper we consider how optics can be used to scale capacity and reduce power in a router. We start with the promising load-balanced switch architecture proposed by C-S. Chang. This approach eliminates the scheduler, is scalable, and guarantees 100% throughput for a broad class of traffic. But several problems need to be solved to make this architecture practical: (1) Packets can be mis-sequenced, (2) Pathological periodic traffic patterns can make throughput arbitrarily small, (3) The architecture requires a rapidly configuring switch fabric, and (4) It does not work when linecards are missing or have failed. In this paper we solve each problem in turn, and describe new architectures that include our solutions. We motivate our work by designing a 100Tb/s packet-switched router arranged as 640 linecards, each operating at 160Gb/s. We describe two different implementations based on technology available within the next three years
A miniaturized dual-axis confocal fluorescence microscope incorporating a broadband catadioptric optical system for detection of multiple fluorophores over broad spectral ranges in VIS and NIR
No full textTunable optical bandpass filter with high-quality vertical mirrors microassembled on movable MEMS platform
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