Optics and Photonics Essential Technologies for Our Nation (2013) / Chapter Skim
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8 Advanced Photonic Measurements and Applications
8 Advanced Photonic Measurements and Applications
Pages 226-247
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From page 226... ...
For example, the NIST-F1 cesium time standard in use in the United States since 1998, around the time of the publication of the National Research Council's (NRC's) report Harnessing Light: Optical Science and Engineering for the 21st Century,1 exploits laser cooling of cesium atoms, optical monitoring of fluorescence, and various other optical techniques to lock in the microwave frequency of the atomic clock, and a second generation of such a system is under construction.2 This chapter describes the advances made in these technologies since 1997.
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From page 227... ...
Now this capability is a commonplace consumer item found in cell phones, car navigation equipment, and even pet identification tags. GPS relies on preci sion timing to enable high-resolution positioning, which also enables high data rates and long-range communications.
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From page 228... ...
One example will be low-cost medical sensing devices that leverage consumer electronics components. Since the NRC's 1998 study, advances in octave-spanning optical combs have enabled a small table-top apparatus that provides a direct link between RF and optical frequency and time standards -- apparatus that used to take several rooms full of specialized equipment.
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From page 229... ...
Such advanced photon-counting techniques need to be expanded not only to higher count rates but to exploitation of novel quantum states of light in advanced optical sensors that are likely to come onto the horizon in the next decade or so.3,4,5 Moreover, current research will potentially provide a true linear-mode single photon detector that will open new doors for sensing, imaging, and metrology. 3 An example is the planned incorporation of squeezed quantum states of light in the advanced Laser Interferometer Gravitational Wave Observatory (LIGO)
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From page 230... ...
While the new scientific developments are breathtaking and will continue to spawn new directions in advanced photonic measurements and applications in laboratories worldwide, it is the category of transitioning to mass-market devices that might have a much greater impact on the economy and people's daily qual ity of life. Imagine an optics-enabled attachment to one's cell phone that allows monitoring of blood glucose by simply inserting a finger into an orifice in the attachment, thereby avoiding pricking one's finger several times a day.
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From page 231... ...
; • Development of attosecond pulse trains by means of high-harmonic generation; • Table-top availability of extreme intensities by means of chirped pulse amplification; • Terahertz and middle-infrared sources of radiation (for example, quantum cascade lasers) ; • High-power fiber lasers; • Advances in non-linear optics, quasi-phase matching, photonic bandgap fibers, and magneto-optics; • Nano optics and plasmonics, negative index materials, and transformation optics; • Advances in controlled generation of quantum light states and their ma nipulation and detection; • Advances in detector technologies, wider wavelength coverage, pixel count, quantum limited operation, and single-photon and photon-number re solved counting; • Advances in adaptive optical techniques, guide stars, deformable mirrors, and turbulence control; and • Computational imaging and sensing.
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From page 232... ...
CHANGES SINCE HARNESSING LIGHT There have been significant changes in advanced photonic measurements and applications since the publication of Harnessing Light.11 The changes have created new capabilities, improved the resolution and precision of measurements, and provided capabilities to modest facilities that were previously available in only a few locations around the world. Some of the significant changes are highlighted here.
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have created table-top sources of coherent x rays14 by such methods of extreme nonlinear optics.15 Such x-ray light sources are likely to have a revolutionary impact on such applications as imaging and lithography on the nanoscale.
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2010. High-harmonic generation: Ultrafast lasers yield x rays.
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Structures with controlled dimensions from tens to hundreds of nanometers fab ricated in dielectrics, semiconductors, and metals17 allow a broad range of new optical possibilities, such as photonic crystal structures, metamaterials,18 compact high-quality-factor micro-ring resonators, and other nanometallic and plasmonic structures.19 Those approaches offer new ways of concentrating or manipulating light20 for enhancing or controlling sensing of various kinds,21 such as chemical sensors, or such techniques as Raman scattering, and allow us to tailor optical response, such as spectral sensitivity, in ways beyond conventional optics. The science and basic technology of many such opportunities have been increasingly explored in research over the last decade as various nanofabrication tools have become more available.
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From page 236... ...
exit the laser at random times, forming a Poisson distributed stream of photons even though the emitted light beam has constant power in the case of a continuous-wave laser. At the macroscopic level, the EM field associated with the emitted light wave approaches a sinusoid much like that seen on a string when it is repetitively shaken.
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From page 237... ...
The use of squeezed light can lead to enhanced performance, and a prototype demonstration of the expected enhancement has been made (see Figure 8.2) .33,34 It is expected that the use of this novel quantum state of light will play a pivotal role in the ultimate detection of gravity waves and in the opening of a new window on the universe.
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2011. A gravitational wave observatory operating beyond the quantum shot-noise limit.
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From page 239... ...
is a technology that is used to improve the performance of optical systems by reducing the effect of wavefront distortions. It works by measuring the distortions in a wavefront and compensating for them with a device that corrects the errors, such as a deformable mirror or a liquid-crystal array."38 Tremendous advances continue to occur in the technology and applications of adaptive optics.39 For example, in the not-too-distant future, a patient may, after having cataract surgery, be able to have a personalized aberration corrected lens implanted that would give the person better vision than she or he had been born with.40 Identification of Technological Opportunities from Recent Advances The ultimate technical challenge in sensing is to be able to detect something even at very low levels or with very high specificity, such as trace concentrations of toxic pollutants in the atmosphere, a specific biochemical structure, vibrations on the fuselage or wings of an airplane in order to gain early indications of crack for mation, or variations in Earth's gravity to facilitate a search for oil or other hidden objects.
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From page 240... ...
Cost-Effective Biomedical Sensing Devices The general field of nanophotonics is likely to remain promising and active in research in coming years for biochemical and biomedical sensing. Because many nanopatterning and nanofabrication tools (such as optical lithography developed for IC fabrication and other novel techniques, such as nanoimprint lithography42)
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:6641-6647. 45 For example, it is possible to reduce shot noise by means of squeezed light injection in the LIGO; this is leading to enhanced sensitivity in the quest for the detection of the gravity waves.
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From page 242... ...
For example, there is the possibility of using entangled photons for creating shared secrets between remote users for the purpose of communicating securely.51 Such techniques of quantum cryptography have been demonstrated and are being commercialized,52,53 and there is much potential for ensuring the privacy of communications in ways that are tamperproof.54 However, much more research and technology development need to happen before the promise of global-scale, highly secure communications protected by the fundamental laws of quantum physics can be realized. For example, the current systems have limited reach ow ing to the lack of a suitable quantum repeater technology -- unlike the ubiquitous optical amplifiers in the case of conventional optical communications -- and are slow owing to poor quantum efficiency and low speed of single-photon detectors.
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From page 243... ...
funding agencies, once a leader in free-space quantum cryptography and communications, so far have announced no plans.55 The fundamental quantum nature of light is such that our ability to produce light beams with prearranged photonic structure (light of a specified quantum state) is intimately tied to our ability to measure the arrangement of photons in a light beam.
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From page 244... ...
However, the proliferation of devices developed for consumer products presents a significant marketing opportunity. Many niche sensor markets could not be addressed without the capabilities enabled by these devices.
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From page 245... ...
One example is in biomedical sensing in which low-volume manufacturing of devices could efficiently be maintained within the United States by leveraging high-volume consumer components, such as the high-resolution networked imagers now almost universally available in the form of cell phone cameras. Exploiting this advanced technology could enable portable and/or remote health monitoring and diagnosis.
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From page 246... ...
Key Recommendation: The United States should develop the technology for gen erating light beams whose photonic structure has been prearranged to yield better performance in applications than is possible with ordinary laser light. Prearranged photonic structures in this context include generation of light with specified quantum states in a given spatiotemporal region, such as squeezed states with greater than 20-dB measured squeezing in one field quadrature, Fock states of more than 10 photons, and states of one and only one photon or two and only two entangled photons with greater than 99 percent probability.
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From page 247... ...
funding agencies should continue to support fundamental research in optics and photonics. Important subjects for future research include nanophotonics, extreme nonlinear optics, and number-resolving photon counters for a truly linear-mode single-photon detector.
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