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Optical power

About: Optical power is a research topic. Over the lifetime, 15299 publications have been published within this topic receiving 145999 citations. The topic is also known as: focusing power.


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Journal ArticleDOI
TL;DR: In this article, the fundamental working equations required to describe the associated power transfer are derived and the application of this geometry to a variety of optical phenomena including add/dropping of optical beams, add/drop filtering and optical power switching are discussed.
Abstract: The most basic and generic configuration, which consists of a unidirectional coupling between a ring resonator and a waveguide, is considered. The fundamental working equations required to describe the associated power transfer are derived and the application of this geometry to a variety of optical phenomena is discussed. These phenomena include 'add/dropping' of optical beams, add/drop filtering and optical power switching.

1,108 citations

Journal ArticleDOI
TL;DR: Berge and Peseux as discussed by the authors used electrocapillarity in order to change the contact angle of a transparent drop, thus realizing a lens of variable focal length, with a typical response time of 0.03 s and a dissipated power of a few mW.
Abstract: We use electrocapillarity in order to change the contact angle of a transparent drop, thus realizing a lens of variable focal length (B. Berge, J. Peseux, Patent deposited in Grenoble France, October 8th 1997, numero d'enregistrement national 97 12781). The key point is the application of gradients of wettability, which control the shape of the drop edge, in our case a centered circle of variable radius. The quality and reversibility of the lens are surprisingly good. The optical power variation can be 5 to 10 times the one of the human eye, for a comparable diameter, with a typical response time of 0.03 s and a dissipated power of a few mW.

1,078 citations

Journal ArticleDOI
TL;DR: In this article, a near-field transducer with efficient optical energy transfer was used to record a 70-nm track above the Curie point in nanoseconds and record data at an areal density of ∼375 Tb/m−2.
Abstract: Although near-field microscopy has allowed optical imaging with sub-20 nm resolution, the optical throughput of this technique is notoriously small. As a result, applications such as optical data storage have been impractical. However, with an optimized near-field transducer design, we show that optical energy can be transferred efficiently to a lossy metallic medium and yet remain confined in a spot that is much smaller than the diffraction limit. Such a transducer was integrated into a recording head and flown over a magnetic recording medium on a rotating disk. Optical power from a semiconductor laser at a wavelength of 830 nm was efficiently coupled by the transducer into the medium to heat a 70-nm track above the Curie point in nanoseconds and record data at an areal density of ∼375 Tb m−2. This transducer design should scale to even smaller optical spots. Using a near-field transducer with efficient optical energy transfer, researchers demonstrate proof-of-principle heat-assisted magnetic recording with multi-track data density of ∼375 Tb m−2.

860 citations

Journal ArticleDOI
TL;DR: In this article, it is shown that a proper front-end design incorporates a high-impedance preamplifier which tends to integrate the detector output, and this must be followed by proper equalization in the later stages of the linear channel.
Abstract: This paper is concerned with a systematic approach to the design of the “linear channel” of a repeater for a digital fiber optic communication system. In particular, it is concerned with how one properly chooses the front-end preamplifier and biasing circuitry for the photodetector; and how the required power to achieve a desired error rate varies with the bit rate, the received optical pulse shape, and the desired baseband-equalized output pulse shape. It is shown that a proper front-end design incorporates a high-impedance preamplifier which tends to integrate the detector output. This must be followed by proper equalization in the later stages of the linear channel. The baseband signal-to-noise ratio is calculated as a function of the preamplifier parameters. Such a design provides significant reduction in the required optical power and/or required avalanche gain when compared to a design which does not integrate initially. It is shown that, when the received optical pulses overlap and when the optical channel is behaving linearly in power,1 baseband equalization can be used to separate the pulses with a practical but significant increase in required optical power. This required power penalty is calculated as a function of the input and equalized pulse shapes.

700 citations

Journal ArticleDOI
01 Feb 1996
TL;DR: In this paper, a phase profile is imposed on an optical beam as it is either transmitted through or reflected from the phase shifter array, and the imposed phase profile steers, focuses, fans out, or corrects phase aberrations on the beam.
Abstract: Optical phased arrays represent an enabling new technology that makes possible simple affordable, lightweight, optical sensors offering very precise stabilization, random-access pointing programmable multiple simultaneous beams, a dynamic focus/defocus capability, and moderate to excellent optical power handling capability. These new arrays steer or otherwise operate on an already formed beam. A phase profile is imposed on an optical beam as it is either transmitted through or reflected from the phase shifter array. The imposed phase profile steers, focuses, fans out, or corrects phase aberrations on the beam. The array of optical phase shifters is realized through lithographic patterning of an electrical addressing network on the superstrate of a liquid crystal waveplate. Refractive index changes sufficiently large to realize full-wave differential phase shifts can be effected using low (<10 V) voltages applied to the liquid crystal phase plate electrodes. High efficiency large-angle steering with phased arrays requires phase shifter spacing on the order of a wavelength or less; consequently addressing issues make 1-D optical arrays much more practical than 2-D arrays. Orthogonal oriented 1-D phased arrays are used to deflect a beam in both dimensions. Optical phased arrays with apertures on the order of 4 cm by 4 cm have been fabricated for steering green, red, 1.06 /spl mu/m, and 10.6 /spl mu/m radiation. System concepts that include a passive acquisition sensor as well as a laser radar are presented.

689 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202365
2022159
2021307
2020641
2019753
2018702