[Encyclopedia Of Laser Physics And Technology

[Iberio Ralda]

<div>The RP Photonics Encyclopedia (formerly Encyclopedia of Laser Physics and Technology) is an encyclopedia of optics and optoelectronics, laser technology, optical fibers, nonlinear optics, optical communications, imaging science, optical metrology, spectroscopy and ultrashort pulse physics.[1] It is available online as a free resource. An earlier version of the encyclopedia appeared as a two-volume book.[2] As of March 2024[update], the online version of the encyclopedia contains 1043 articles.</div><div></div><div></div><div></div><div></div><div></div><div>Encyclopedia of Laser Physics and Technology</div><div></div><div>Download Zip: https://t.co/tvZiM0bYDe </div><div></div><div></div><div>Since 2012, the encyclopedia is closely interlinked with the RP Photonics Buyer's Guide, a large directory of photonics product suppliers.[3] For the majority of products, there is a one-to-one correspondence between an encyclopedia article and a listing of suppliers for that product.</div><div></div><div></div><div>Other resources linked with the RP Photonics Encyclopedia are a blog named The Photonics Spotlight,[4] a glossary of photonics terms and acronyms,[5] various tutorials,[6] and a photonics quiz.[7]</div><div></div><div></div><div>Hosted by RP Photonics Consulting GmbH and compiled by Rdiger Paschotta, this encylcopedia covers basic terminology and principles of laser physics and technology as well as topics in general optics and optoelectronics, nonlinear optics, quantum optics, fiber optics, and optical communications.</div><div></div><div></div><div>The best book for beginners to learn about lasers is "Understanding Lasers: An Entry-Level Guide" by Jeff Hecht. This book covers the basics of laser technology, including the principles of light, types of lasers, and applications of lasers in various fields.</div><div></div><div></div><div>Yes, "Principles of Lasers" by Orazio Svelto is a highly recommended book for a more comprehensive understanding of lasers. This book covers advanced topics such as laser resonators, modes, and amplifiers, as well as practical applications and future developments in laser technology.</div><div></div><div></div><div></div><div></div><div></div><div></div><div>Yes, "Medical Applications of Lasers" by Wolfgang Bumler and Karl-Michael Haase is a great resource for learning about the use of lasers in medicine. This book covers topics such as laser-tissue interactions, laser surgery, and laser therapy for various medical conditions.</div><div></div><div></div><div>"The Laser Inventor's Handbook" by Anthony E. Siegman is a comprehensive book that not only covers the history of lasers but also delves into the scientific principles and practical applications of lasers. It is a valuable resource for anyone interested in the development and evolution of laser technology.</div><div></div><div></div><div>Yes, "Build Your Own Laser, Phaser, Ion Ray Gun" by Robert Iannini is a fun and informative book that includes step-by-step instructions for building your own laser devices using common household materials. It also provides explanations of the science behind laser technology and suggestions for further experimentation.</div><div></div><div></div><div>Driven by the desire to characterize the electronic and vibronic properties of new materials with nanometer resolution, photonics researchers go through considerable effort to continuously refine nanoimaging techniques. Tip-enhanced Raman spectroscopy (TERS) is an approach that has been well recognized and relies on strongly localized enhancement of Raman scattering of laser light at the point of a near-atomically sharp tip. However, not least due to the lack of sources that would deliver laser light conveniently tunable throughout the visible spectral range, the vast majority of TERS experiments so far has been limited to single excitation wavelengths.</div><div></div><div></div><div>A recent study now demonstrates excitation-dependent hyperspectral imaging, exemplified on carbon nanotubes, by implementing a tunable continuous-wave optical parametric oscillator into a TERS setup. We take a closer look at the laser technology behind the experiment and illustrate the vast potential of the method.</div><div></div><div></div><div>Optical parametric oscillators (OPOs) might be considered as light sources that deliver coherent radiation very similar to lasers, but with two main differences between the devices.1 First, the OPO principle relies on a process referred to as parametric amplification in a nonlinear optical material, rather than on stimulated emission in a laser gain medium. Second, OPOs require a coherent source of radiation as a pump source, unlike lasers, which can be pumped with either incoherent light sources or sources other than light.</div><div></div><div></div><div>Figure 1 illustrates the basic scheme common to OPOs and other optical parametric devices. The process can be perceived as splitting of an incoming pump photon of high energy into two photons of lower energy, the latter usually referred to as signal and idler photons, respectively. It is essential to note that the overall process is subject to the conservation principles of photon energy and photon momentum (phase-matching condition), but otherwise does not have further fundamental restrictions, at least in theory. The huge potential of OPOs thus derives from their exceptional wavelength versatility, as they are in principle not limited by the wavelength coverage dictated by the energy levels and suitable transitions in a laser gain medium.</div><div></div><div></div><div>In practice, the OPO concept was experimentally demonstrated already more than half a century ago,2 but the progress in development and commercialization of turnkey devices has been stalled substantially by several technical obstacles.3 These obstacles have been easier to overcome at the high peak powers of pulsed devices, so that tunable OPOs operating in pulsed mode have become readily available from a variety of suppliers. Only relatively recently have there been comparable advances in continuous-wave (CW) OPO technology, which have spurred the development of commercial systems.</div><div></div><div></div><div>This progress has been mainly driven, on the one hand, by the increasing availability of cost-effective high-performance CW pump lasers and, on the other hand, by the advent and increasingly sophisticated design of new nonlinear crystals. As to pump lasers, the operation of CW OPOs puts stringent requirements on potential light sources in terms of preferential single-mode operation, noise characteristics, beam quality, and beam pointing stability.</div><div></div><div></div><div>Depending on power requirements of the end user, either high-performance diode-pumped solid-state (DPSS) lasers (for lower powers) or fiber-laser-based solutions (for higher powers) are typically used. As for nonlinear materials and novel crystal design techniques, it should be noted that the emergence of so-called quasi-phase-matched nonlinear materials like periodically poled lithium niobate (PPLN), whose crystal structure alternates with a certain periodicity, has been of great utility for the design of practical optical parametric devices.</div><div></div><div></div><div>While OPO technology appears to be ideally suited for generating tunable CW laser light across arbitrary wavelength ranges, one must keep in mind that the OPO process itself will always generate output at wavelengths that are longer than those used for pumping. Consequently, OPO devices operating across the visible spectral range either require UV pump sources or, alternatively, need to employ additional frequency conversion stages. As of now, only the latter approach has been proven to be technically practicable and operationally stable in commercial turnkey systems.</div><div></div><div></div><div>As shown in Figure 2, this wavelength conversion takes place in a second, separate cavity by frequency doubling of the primary OPO cavity output, a process widely known as second-harmonic generation (SHG). Though this configuration is technically practicable and provides favorable operational stability, it should be mentioned that alternative designs, like intracavity frequency doubling, have been successfully demonstrated in the lab.</div><div></div><div></div><div>Raman scattering has been well established as one of the main techniques to identify the chiral vectors of CNTs experimentally.6 So-called radial breathing modes (RBMs) that correspond to collective movements of carbon atoms in the radial direction serve as fingerprints of particular (n,m) configurations in the Raman spectrum.</div><div></div><div></div><div>The three main components of a TERS setup include: A laser light source for excitation, an atomic-force microscope (AFM) equipped with a sharp metallic tip, and a Raman spectrometer recording the inelastically scattered radiation.5 The basic physical principle behind TERS relies on so-called localized surface plasmons that are excited by the laser light in the microscope tip. These plasmons generate a strongly localized electromagnetic field, which not only enhances the incoming and Raman-scattered radiation by orders of magnitude, but also ensures a highly localized excitation of the sample under study. Thus, by recording tip-enhanced Raman spectra intensities as a function of the tip position, TERS allows for nanoimaging with a spatial resolution down to below 10 nm.</div><div></div><div></div><div>For a spatial image of the particular CNT, the outlined procedure is repeated: The tip position is scanned stepwise over the sample surface and at each point the intensity of the pure tip-enhanced Raman peak determined. Figure 4b shows the result of such a scan and images the position of a (7,5) CNT in a 550 140 nm2 area. As can be seen, the CNT is around 800 nm long and bent in a steplike shape.</div><div></div><div></div><div>The full beauty of the experimental approach now unfolds when realizing that the imaging capability of the setup is no longer limited to a subset of CNTs that happen to be in electronic resonance to a particular excitation wavelength, as has been the case for the vast majority of TERS experiments. On the contrary, the examination of the sample under study can be in principle performed for a quasi-continuum of wavelengths that is covered by the tunable laser light source.</div><div></div><div></div><div>Jaroslaw Sperling is business developer for femtosecond fiber lasers at Menlo Systems (Martinsried, Germany). With a background in ultrafast laser spectroscopy, he holds a Ph.D. in physical chemistry from the University of Vienna (Austria).</div><div></div><div></div><div>The laser is a device that uses the principle of stimulated emission to produce light. The qualities of the light generated by a laser are significantly different from that generated by a conventional source such as an incandescent light bulb or fluorescent light tube. These major differences include:</div><div></div><div> 795a8134c1</div>