We describe the operation and performance of a dual fiber optical trap created using tapered lensed optical fibers pigtailed to 1300 nm laser diodes. Single-mode fibers, having mode field diameters of ∼9.5 μm, and separated by up to 350 μm, are used to demonstrate dielectric particle confinement over two orders of magnitude in fiber trapping power ratio. Axial and transverse trap efficiencies, as well as the existence of bistable trapping positions, are predicted and experimentally confirmed. The use of fiber lenses results in the creation of an optical trap that provides strong transverse optical confinement and which is nearly insensitive to the fiber polarization state.
We demonstrate a multi-functional optical trap capable of trapping, motion control, position sensing and fluorescence detection of chemically treated polystyrene beads, using off-the-shelve optical components. It consists of two collinearly aligned single-mode fibers separated by a spacing of 130-170mum for trapping, another single-mode fiber for probing/pumping and a fourth multi-mode fiber for optical detection. The fibers are mounted either on V-grooved Si or PDMS platforms fabricated using microfabrication and molding techniques, respectively. The result represents an important milestone towards a functional integrated trapping platform.
As routing tables in core Internet routers grow to exceed 100 000 entries, it is becoming essential to develop methods to reduce the lookup time required to forward packets toward their destinations. In this paper, we employ a bank of novel thermally tuned fiber-Bragg-grating-based optical correlators to construct an "optical bypass" to accelerate conventional electronic Internet routers. The correlators are configured as a routing table cache that can quickly determine the destination port for a fraction of the incoming traffic by examining only a subset of the bits in an IP packet's 32-bit destination address.We also demonstrate a novel multiwavelength correlator based on fiber Bragg grating that can simultaneously recognize the header bits on multiple wavelengths for use in wavelength-division-multiplexed (WDM) systems. Using the optical bypass, routing table lookup times are reduced by an order of magnitude from microseconds to nanoseconds and are limited only by the speed of the optical switch. Index Terms-Optical communications, optical correlators, optical signal processing, wavelength-division-multiplexed (WDM) networks. I. INTRODUCTION I N present-day fiber-optic networks, data packets are converted to electrical form at each node to process their headers and make routing decisions, as shown in Fig. 1(a). As routing tables grow in size, more memory accesses are required to determine the next-hop address and appropriate output port to which to forward each packet. The associated increase in routing-table lookup times is becoming a significant source of latency in the network core. To make matters worse, the transmission capacity of optical fibers is rapidly increasing, forcing the routers to accommodate more packets, more often. Since routing tables will Manuscript
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