Optical Maser Research Articles

Investigating Asymmetry Development from SiO to H2O Maser Regions in VX Sagittarii

Simultaneous very-long-baseline interferometry monitoring observations of H2O and SiO masers toward VX Sagittarii were conducted from 2014 February to 2019 January. Thirty epochs of observations revealed that the H2O and SiO masers had asymmetric and ring-like structures, respectively. However, from 2017 September to 2018 March, the SiO maser transformed from a ring-like structure to a northeast–southwest (NE–SW) extension, and the 43.1 and 86.2 GHz SiO maser components had velocities of 39.48 and 10.65 km s−1 in the NE–SW direction, suggesting a possible localized strong shock wave. The H2O maser had a double-sided structure oriented in the NE–SW direction with near-stellar velocity components, which aligned with the extended direction of the SiO maser. The nonregular optical brightness and maser intensity variations were speculated to be related to the morphological evolution of the SiO maser. During the stable states attained by regular pulsations, the SiO maser region was presumed to experience radial acceleration, which reverted the SiO maser to a ring-like structure. However, the H2O maser region, where the acceleration almost terminates, retained its asymmetric morphology due to the prior influence of external forces. The results suggest that substantial energy transfer can alter the dynamics of the SiO maser and surrounding atmosphere, leading to an asymmetric distribution in the H2O maser region.

Absolute frequency measurements with a robust, transportable 40Ca+ optical clock

We constructed a transportable 40Ca+ optical clock (with an estimated minimum systematic shift uncertainty of and a stability of ) that can operate outside the laboratory. We transported it from the Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan to the National Institute of Metrology, Beijing. The absolute frequency of the 729 nm clock transition was measured for up to 35 d by tracing its frequency to the second of International System of Units. Some improvements were implemented in the measurement process, such as the increased effective up-time of 91.3% of the 40Ca+ optical clock over a 35-day-period, the reduced statistical uncertainty of the comparison between the optical clock and hydrogen maser, and the use of longer measurement times to reduce the uncertainty of the frequency traceability link. The absolute frequency measurement of the 40Ca+ optical clock yielded a value of 411 042 129 776 400.26 (13) Hz with an uncertainty of , which is reduced by a factor of 1.7 compared with our previous results. As a result of the increase in the operating rate of the optical clock, the accuracy of 35 d of absolute frequency measurement can be comparable to the best results of different institutions in the world based on different optical frequency measurements.

Gold-silver alloy hollow nanoshells-based lateral flow immunoassay for colorimetric, photothermal, and SERS tri-mode detection of SARS-CoV-2 neutralizing antibody

Although many approaches have been developed for the quick assessment of SARS-CoV-2 infection, few of them are devoted to the detection of the neutralizing antibody, which is essential for assessing the effectiveness of vaccines. Herein, we developed a tri-mode lateral flow immunoassay (LFIA) platform based on gold–silver alloy hollow nanoshells (Au–Ag HNSs) for the sensitive and accurate quantification of neutralizing antibodies. By tuning the shell-to-core ratio, the surface plasmon resonance (SPR) absorption band of the Au–Ag HNSs is located within the near infrared (NIR) region, endowing them with an excellent photothermal effect under the irradiation of optical maser at 808 nm. Further, the Raman reporter molecule 4-mercaptobenzoic acid (MBA) was immobilized on the gold–silver alloy nanoshell to obtain an enhanced SERS signal. Thus, these Au–Ag HNSs could provide colorimetric, photothermal and SERS signals, with which, tri-mode strips for SARS-CoV-2 neutralizing antibody detection were constructed by competitive immunoassay. Since these three kinds of signals could complement one another, a more accurate detection was achieved. The tri-mode LFIA achieved a quantitative detection with detection limit of 20 ng/mL. Moreover, it also successfully detected the serum samples from 98 vaccinated volunteers with 79 positive results, exhibiting great application value in neutralizing antibody detection.

The Graphical Results of Myopia after Refractive Surgical Treatment by Femto2nd Optical Maser-Assisted and Epiboly’s LASEK (Eye-Surgery) have Remained Comparable.

Background: In this prospective cohort study (flap-off epi-eye-surgery), the results of femtosecond optical maser-assisted in situ keratomileusis (femto-eye-surgery) and epipolis eye-surgery refractile surgery for myopia were compared.
 Purpose: Comparison of the results of eye-surgery myopia or myopic astigmia improvement by a six- multidimensional amaris exciter optical maser and establish that both femto- eye-surgery and flap-off epi-eye-surgery are safe, effective, and predictable in Amanat eye hospital Rawalpindi. The duration of the study was July 2019- July 2021. Sample size was 400 eyes, 200 patients, 81 male and 119 female. The study was conducted after the ethical approval of the hospital ethical committee.
 Methods: Four hundred (400) eyes from 200 individuals were divided into two groups in this prospective cohort study. For femto-eye-surgery flaps, a femtosecond optical maser was used, while an epikeratome (flap-off) was used for epi-eye-surgery flaps. The researchers measured uncorrected distance graphicalacuity (u.d.v.a), corrected distance graphical acuity (c.d.v.a), visible bending (m.r), corneal asphericity (q-value), and corneal higher-order aberrations (hoas) before and after surgery. In both groups, the improvement in logmar udva following refractile surgery was statistically significant (p< 0.001 for all); it was significantly higher for femto-eye-surgery 1 day and 1 week postoperatively (p <0.001 for femto-eye-surgery, respectively).
 Results: Logarithm of the minimum angle of resolution (logmar) of udva after refractile surgery was statistically significant for both groups (p = 0.002); it was significantly higher for femto-eye-surgery than flap-off epi-eye-surgery (0.03 *0.06 logmar (femto-eye-surgery) and 0.54 * 0.31 logmar (flap-off epi-eye-surgery ) at 1 day postoperatively; 0.02 *0.05 logmar (f the increase in spherical aberration (z4,0) in flap-off epi-eye-surgery was reater than femto-eye- surgery : 0.626 ± 0.232 μm and 0.479 ± 0.139 μm in the front cornea; 0.556 ± 0.227 μm and 0.430 ± 0.137 μm in the total cornea (p = 0.016 and p = 0.017). There was no significant impact of the changes to the corneal hoa in the back of the eye on the corneal hoa in general.
 Conclusion: Despite the fact that femto-eye-surgery generated better early graphics results than flap-off epi-eye-surgery, there was no significant difference in the results one week following surgery.

The Invention of the Laser.

In this chapter, I describe a scientific rivalry at Columbia University's physics department in the days of the 1950s before and when the laser invented, and the race to build a laser eventually won by a scientist in California in 1960. It tracks the arc from Charles Townes' success in amplifying microwaves with a device he called the maser, to graduate student Gordon Gould's realization of how shorter and more powerful light waves could also be amplified. The chapter describes Gould's notebook, written in 1957, diagramming an optically pumped laser. In the same notebook, he coined the word laser, an acronym for light amplification by stimulated emission of radiation, and suggested possible uses for the coherent light beams he imagined. The chapter also covers Gould's wish to patent and profit from his invention, his mistaken belief that he had to build a laser to receive a patent, and the flirtation with radical politics that barred him from the laboratory where he worked once the government classified the laser project that it was funding. Townes and his colleague and brother-in-law Arthur Schawlow, both eventual Physics Nobelists, meanwhile filed an application and received a patent for what they called an optical maser. Theodore Maiman at Hughes Laboratories built the first working laser in 1960, as the chapter describes. It concludes with the results of Gould's long battle to win basic laser patents and his eventual success.

Trash Sweep Medi-waste separator

Lately, robotized cleaners have taken huge thought in mechanical innovation ask about due to their reasonability in aiding individuals in floor cleaning applications at homes, lodgings, restaurants, working environments, facilities, studios, dispersion focuses and universities. In a general sense, mechanized cleaners have their cleaning functions like floor cleaning, dry vacuum cleaning and dust removal. A couple of things rely upon fundamental obstruction avoidance using sensors while few utilize laser planning strategy. Every spring-cleaning and working instrument of computerized base cleansers has its own focal points and blocks. For instance, robots exploiting optical maser planning are respectably faster, less dreary and imperativeness capable yet expensive, while obstacle avoiding based robots are monotonous and less essentialness viable on account of sporadic cleaning anyway less excessive. Multi-Nations are course back in collecting mechanical cleaners. Getting them from abroad extends their costs. The essential objective of this work is to offer a better response with limited available resources and cost. This work likewise centers around cleaning strategies in clinics through attractions strategy and isolating the waste in a less time efficient manner.

A Review on 3D printing Pharmaceutical Manufacturing and applications on Drug Delivery System

Numerous analysts have endeavored to utilize computer supported structure (Computer assisted design) or CAD and computer helped fabricating (CAM) to know a framework that provides a three-dimensional (3D) condition for recovery of tissues and organs. Therefore, a number of 3D printing advances, as well as stereo lithography, testimony displaying, inkjet-based printing and specific optical maser sintering are created. Since these 3D printing advancements use PCs for structure and manufacture, and that they will produce 3D platforms as structured; as a result, they will be institutionalized. Development of target tissues and organs needs the distance of fitting development factors; therefore manufacture of 3D platform frameworks that discharge these bimolecular has been investigated. The medication was created utilizing Pennsylvania-based Aprecia Pharmaceutical's exclusive ZipDose innovation, that expands once existing 3DP analysis did by MIT into creating fast dissolving materials. Even so empowering the generation of more and more compelling portion organizes; the innovation is at risk of have a key influence within the pharmaceutical business ’flip towards low-volume generation and customized prescription. Going higher than and on the far side, on-request medicates printing offices at centers and drug stores, or maybe in patients ’homes, may allow specialists to reinforce treatment by creating made-to-order dosing regimens. What are additional, parts might be made-to-order with singular hues, flavors and shapes to talk to person understanding which can support their adherence. As 3D printing capacities grow any, security and body issues ar attended and therefore the expense of the innovation falls besides contract manufacturers and pharmaceutical organizations that explore totally different avenues relating to these 3D printing developments are likely to choose up an aggressive edge.

Spectroscopic Properties of Yb3+/Nd3+ Co-doped Ions in SiO2-Al2O3-Na2CO3-SrF2-CaF2 Oxyfluoride Glasses for Photonic Applications

The Yb3+ and Yb3+/Nd3+ co-doped SiO2-Al2O3-Na2CO3-SrF2-CaF2 oxyfluorosilicate glasses have been prepared by high temperature melt-quenching method. The prepared glasses are excited with 808 nm, and the near infrared emission bands are observed. The intensified emission band was centered at 1030 nm (2F5/2 -> 2F7/2) of Yb3+ ions. Stimulated emission cross-section was evaluated for the prominent 2F5/2 -> 2F7/2 transition of Yb3+ ion by using the Mc-Cumber theory. The energy transfer from Nd3+ to Yb3+ ions in co-doped silicate based oxyfluoride glasses are described under the 514 nm excitation wavelength. Full Text: PDF ReferencesN. Chiodini, A. Paleari, G. Brambilla, E. R. Taylor, "Erbium doped nanostructured tin?silicate glass?ceramic composites", Appl. Phys. Lett. 80, 4449 (2002). CrossRef D. Jaque, J. Capmany, F. Molero, Z. D. Luo, J. G. Sole, "Up-conversion luminescence in the Nd3+:YAB self frequency doubling laser crystal", Opt. mater. 10, 211 (1998). CrossRef H. Lin, G. Meredith, S. Jiang, X. Peng, T. Luo, N. Peyghambarian, E. Yue-Bun Pun, "Optical transitions and visible upconversion in Er3+ doped niobic tellurite glass", J. Appl. Phys. 93, 186 (2003) CrossRef Atul D. Sontakke, K. Annapurna, "Phonon assisted effective non-resonant energy transfer based 1 ?m luminescence from Nd3+?Yb3+ codoped zinc?boro?bismuthate glasses", J. Lumin. 138, 229 (2013). CrossRef F. Liegard, J.L. Doualan, R. Moncorge, M. Bettinelli, "Nd3+ ? Yb3+ energy transfer in a codoped metaphosphate glass as a model for Yb3+ laser operation around 980 nm", Appl. Phys. B 80, 985 (2005) CrossRef A. Miguel, B. Fan, R. Balda, X. Zhang, J. Fernandez, J.L. Adam, "Spectroscopy and energy transfer in Nd3 +/Yb3 + codoped chalcohalide glasses", J. Non-Cryst. Solids 377, 110 (2013). CrossRef G. Devarajulu, B. Deva Prasad Raju, "Effect of concentration variation on 2.0 ?m emission of Ho3+-doped SiO2?Al2O3?Na2CO3?SrF2?CaF2 oxyfluorosilicate glasses", App. Phy. A, 124 (2018). CrossRef Radoslaw Lisiecki, Elzbiecta Augustyn, Witold Ryba-Romanowski, Michal Zelechower, "Er-doped and Er, Yb co-doped oxyfluoride glasses and glass?ceramics, structural and optical properties", Opt. Mater. 33, 1630 (2011). CrossRef G. Chen, Q. Zhang, G. Yang, and Z. Jiang, "Mid-Infrared Emission Characteristic and Energy Transfer of Ho3+-Doped Tellurite Glass Sensitized by Tm3+", J. Fluoresc. 17, 301 (2007). CrossRef D. E. McCumber, "Theory of Phonon-Terminated Optical Masers", Phys. Rev. 134, 299 (1964). CrossRef D.L. Deloach, S.A. Payne, L.K. Smith, W.L. Kway, W. F. Krupke, "Laser and spectroscopic properties of Sr5(PO4)3F:Yb", J. Opt. Soc. Am. B 11, 269 (1994). CrossRef K. Venkata Krishnaiah, R. Rajeswari, K. UpendraKumar, S. Surendra Babu, I.R. Martin, C.K. Jayasankar, "Spectroscopy and radiation trapping of Yb3+ ions in lead phosphate glasses", J.Quant. Spect. Rad. Trans. 140, 37 (2014). CrossRef

Permanence and boundedness of solutions of quasi-polynomial systems

In this paper we consider analytical properties of a class of general nonlinear systems known as Quasi-Polynomial systems. We analyze sufficient conditions for permanence and boundedness of solutions, and illustrate our approach with an application to Lamb equations describing the evolution of electromagnetic modes in an optical maser.

Mazer’s theory application in Bi4Ge3O12:V

Abstract The recent development of coherent light amplifiers and oscillators, now generally referred to as optical masers “or lasers,” has made feasible a host of new uses and applications of electromagnetic wave energy in the optical portion of the spectrum. Furthermore, the high degree of monochromaticity obtainable from an optical maser makes it a useful tool for spectroscopic investigations as well as for stimulating various types of chemical and physical reactions. The effect of vanadium doping transforms Bi4Ge3O12 single crystals into optical maser. This result can be observed after thermoluminescence at 556 nm.

Charles Hard Townes

Charles Hard Townes

Wilson Prize article: From vacuum tubes to lasers and back again

The first demonstration of an optical-wavelength laser by Theodore Maiman in 1960 had a transformational impact on the paths that would be blazed to advance the state of the art of short wavelength coherent electron beam-based radiation sources. Free electron lasers (FELs) emerged from these efforts as the electron beam-based realization of the pioneering model of atom-based ``optical masers'' by Schawlow and Townes, but with far greater potential for tunable operation at high power and very short wavelengths. Further opportunities for yet greater capabilities may be inherent in our still growing understanding of the underlying physics. This article focuses on the FEL efforts in which the author was directly and personally involved.

Phosphate Yb3+ doped air-cladding photonic crystal fibers for laser applications

We present two single-mode photonic crystal fibers with air-cladding for laser applications. We developed PCF structures created by replacing respectively one and seven air-holes with 6%mol ytterbium doped glass. With increasing mode area you can increase power level and shorten fiber length in laser construction. We achieved 53 and 19 cm optimum length fiber lasers with 4.7 W and 12.4 W respectively maximum output power. The slope efficiency of the lasers were 15.6% and 42.4%. The use of air-cladding brought very high numerical aperture of pump waveguides in both laser fibers resulting with the value of 0.72 and 0.91 respectively. Full Text: PDF References J. Limpert, O. Schmidt, J. Rothhartd, F. Röser, T. Schreiber, A. Tunnermann, "Extended single-mode photonic crystal fiber lasers", Opt. Express 14, 2715 (2006), CrossRef G. Bouwmans, R. M. Percival, W. J. Wadsworth, J. C. Knight, P. St. J. Russell, "High-power Er:Yb fiber laser with very high numerical aperture pump-cladding waveguide", Appl. Phys. Lett. 83, 817 (2003) CrossRef Y. Yeong, J. K. Sahu, D. N. Payne, J. Nilsson, "Ytterbium-doped large-core fiber laser with 1.36 kW continuous-wave output power", Opt. Express 12, 6088 (2004), CrossRef H.Yin, P. Deng, Y. Zhang, F. Gan, "Determination of emission cross section of Yb 3+ in glasses by the reciprocity method", Mat.Lett. 30, 29 (1997) CrossRef D.E. McCumber, "Theory of Phonon-Terminated Optical Masers", Phys. Rev. 134, 299 (1964) CrossRef D.E. McCumber, "Einstein Relations Connecting Broadband Emission and Absorption Spectra", Phys. Rev. 136, 954 (1964) CrossRef L. Li et al., "Investigation of modal properties of microstructured optical fibers with large depressed-index cores", Opt. Lett. 30, 3275 (2005) CrossRef W. J. Wadsworth et al.,"Very high numerical aperture fibers", Photonics Techn. Lett. 16, 843 (2004) CrossRef L. Zenteno, J.Lightwave Techn. 11, 1435 (1993) Y. Lee, M. J. F. Digonnet, S. Sinha, KE. Urbanek, R. L. Byer, S. Jiang, JSQE 1, 93 (2009)

The Double-ended 750 nm and 532 nm Laser Output from PPLN-FWM

We investigate 750 nm and 532 nm dual-wavelength laser for applications in the internet of things. A kind of optical maser is developed, in which the semiconductor module outputs the 808 nm pump light and then it goes into a double-clad Nd3+ :YAG monocrystal optical fiber through the intermediate coupler and forms a 1064 nm laser. The laser outputs come from both left and right terminals. In the right branch, the laser goes into the right cycle polarization LinNbO3 (PPLN) crystal through the right coupler, produces the optical parametric oscillation and forms the signal light λ1 (1500 nm), the idle frequency light λ2 (3660.55 nm), and the second-harmonic of the signal light λ3 (750 nm). These three kinds of light and the pump light λ4 together form the frequency matching and the quasi-phase matching, then the four-wave mixing occurs to create the high-gain light at wavelength 750 nm. Meanwhile, in the left branch, the laser goes into the left PPLN crystal through the left coupler, engenders frequency doubling and forms the light at wavelength 532 nm. That is to say, the optical maser provides 750 nm and 532 nm dual-wavelength laser outputting from two terminals, which is workable.

An Innovative Accurate Experimental Methodology for Measuring Electronic Charges Based on Optical Principles

A simple device for precise measurement of electronic charges is designed in this paper. The electriferous ball deflect at an angle when placed in a strong electric field and kept balanced. The optical maser then deflect at the same angle through the sensor. The laser light reflect between the two mirrors up and down for many times, enlarging the displacement of the ball. Then the electronic charges of the ball will be precisely attained through geometric and mechanical relationships.

Masers made easy

The technological potential of masers — the microwave equivalents of lasers — has been thwarted by their impractical operating conditions. A solid-state maser that works at room temperature may change that. See Letter p.353 The maser is the microwave-frequency precursor of the now ubiquitous laser — or 'optical maser', as it was once known. But it has had little technological impact compared with the laser, in large part because of inconvenience: masers typically require vacuum and/or low-temperature operating conditions. Overcoming these obstacles would pave the way for significant maser-based innovations, including drastically more sensitive measurements across a range of scientific disciplines, from molecular biology to radio astronomy. And, if the history of the laser is any indication, applications not yet dreamt of. Mark Oxborrow, Jonathan Breeze and Neil Alford have now developed a solid-state room-temperature maser, based on an organic molecular crystal, that should enhance the potential of the maser as a tool for science and technology.

Room-temperature solid-state maser

The invention of the laser has resulted in many innovations, and the device has become ubiquitous. However, the maser, which amplifies microwave radiation rather than visible light, has not had as large an impact, despite being instrumental in the laser's birth. The maser's relative obscurity has mainly been due to the inconvenience of the operating conditions needed for its various realizations: atomic and free-electron masers require vacuum chambers and pumping; and solid-state masers, although they excel as low-noise amplifiers and are occasionally incorporated in ultrastable oscillators, typically require cryogenic refrigeration. Most realizations of masers also require strong magnets, magnetic shielding or both. Overcoming these various obstacles would pave the way for improvements such as more-sensitive chemical assays, more-precise determinations of biomolecular structure and function, and more-accurate medical diagnostics (including tomography) based on enhanced magnetic resonance spectrometers incorporating maser amplifiers and oscillators. Here we report the experimental demonstration of a solid-state maser operating at room temperature in pulsed mode. It works on a laboratory bench, in air, in the terrestrial magnetic field and amplifies at around 1.45 gigahertz. In contrast to the cryogenic ruby maser, in our maser the gain medium is an organic mixed molecular crystal, p-terphenyl doped with pentacene, the latter being photo-excited by yellow light. The maser's pumping mechanism exploits spin-selective molecular intersystem crossing into pentacene's triplet ground state. When configured as an oscillator, the solid-state maser's measured output power of around -10 decibel milliwatts is approximately 100 million times greater than that of an atomic hydrogen maser, which oscillates at a similar frequency (about 1.42 gigahertz). By exploiting the high levels of spin polarization readily generated by intersystem crossing in photo-excited pentacene and other aromatic molecules, this new type of maser seems to be capable of amplifying with a residual noise temperature far below room temperature.

Charles Townes—Nobel Laureate for Maser-Laser Work

The American physicist Charles Hard Townes shared the 1964 Nobel Prize in Physics with 2 Soviet physicists, Aleksandr M. Prokhorov (1916-2002) and his student Nikolay G. Basov (1922-2001), for fundamental work in the field of quantum electronics, which led to the construction of oscillators and amplifiers on the maserlaser principle. Townes conceived the idea of the maser in 1951 and built the first device in 1953. The Soviet scientists, working independently of Townes, provided much of the theoretical work for lasers and masers. These devices have applications as widely varied as high-resolution spectroscopy, length standards, surgery, welding, radar, and communications. Townes, the fourth of 6 children of an attorney, was born on July 28, 1915, on a farm outside Greenville, SC. He attended Furman University in his hometown, receiving both the BS degree in physics and the BA degree in modern languages in 1935, graduating summa cum laude. He then enrolled in Duke University in Durham, NC, and received the MSc degree in physics in 1937. Next, he spent 2 years at the California Institute of Technology in Pasadena, where he was awarded the PhD degree in physics, in 1939, for his thesis on “The Separation of Isotopes and the Determination of the Spin of the Nucleus of Carbon 13.” After receiving his doctoral degree, Townes joined the technical staff of the Bell Telephone Company in New Jersey and worked with that group from 1939 to 1947. During World War II (1939-1945), while with Bell Laboratories, Townes worked on radar bombing systems and microwave spectroscopy and did some early work on radio astronomy. In 1948, Townes joined the faculty of Columbia University in New York City as a teacher of physics. By 1950, he was director of the Columbia Radiation Laboratory, and in 1952, he became chair of the physics department of Columbia University. In 1951, he first had the idea of what would culminate in the construction of a maser ( icrowave amplification by timulated mission of radiation). The first maser device, which used ammonia gas, was built in December 1953. In 1958, Townes and a colleague outlined the principle of the optical maser, or laser. They speculated that a maser could deliver infrared or even visible light instead of microwaves. In 1960, such a device was constructed by the American physicist Theodore H. Maiman (1927-2007), who used a pink ruby rod that emitted intermittent bursts of red light. The device was called “laser” for light amplified by timulated mission of radiation. Lasers were soon used in medicine (certain eye operations), chemical analysis (vaporized small bits of substances for spectroscopic analysis), communications, metal working, instrumentation and measurement, and art and by the military. From 1959 to 1961, while on a leave of absence from Columbia University, Townes served as vice president and director of research at the Institute for Defense Analyses in Washington, DC, where he was concerned with problems of national defense and foreign policy. In 1961, Townes officially left Columbia University and joined the faculty of the Massachusetts Institute of Technology (MIT) in Cambridge, where he was appointed provost and professor of physics. He directed research in nonlinear optics until 1967. In 1967, Townes was appointed professor at the University of California at Berkeley. He initiated a program in radio and infrared astronomy, which led to the discovery of complex molecules (ammonia and water) in the interstellar medium. In 1986, Townes was made professor emeritus. Townes was honored on stamps issued by St Vincent in 1991 (Scott No. 1563d) and by Madagascar in 1993.

Aleksandr Prokhorov—Lasers and Masers

The 1964 Nobel Prize in physics was shared by 3 physicists: Russians Aleksandr Mik hail ovich Prokhorov (1916-2002) and Nikolay G. Basov (1922-2001) and American Charles H. Townes (1915) for fundamental research in quantum electronics that led to the development of the maser and laser. Specifically, Basov and Prokhorov performed the basic research that led to the invention of laser and maser devices, which was accomplished independently by Townes and others. Maser stands for microwave amplication by stimulated emission of radiation; a laser is an optical maser. These devices collect energy waves, amplify them hundreds of times, and produce a beam of almost perfectly parallel waves with little or no interference or static. The principles of the laser and maser have been applied to many fields, including medicine. Prokhorov was born of Russian parents on July 11, 1916, in Atherton in northeastern Queensland, Australia. His father had fled Russia in 1911 after escaping from exile in Siberia. After the Russian Revolution (1917), the family returned to the Soviet Union in 1923. Prokhorov studied physics at Leningrad State University, graduating with the baccalaureate degree in 1939. He then became a graduate student at the P. N. Lebedev Physical Institute in Moscow. However, his studies were interrupted by World War II (1939-1945). He served in the Russian Army from 1941 to 1944. After the war, he returned to school and received his doctorate in 1946 from the P. N. Lebedev Physical Institute in Moscow. After receiving his doctorate, Prokhorov became a senior associate at the Institute. Here, he and Basov, who was Prokhorov’s student, jointly suggested the maser principle of amplifying and emitting parallel electromagnetic waves that are all in phase and all on the same wavelength. About the same time, Townes, at Columbia University in New York City, was independently working out the principle of the maser. Townes was the first to actually build such a device (1954). In 1954, Prokhorov became director of the Oscillation Laboratory at the P. N. Lebedev Institute, and later, he was appointed professor of physics at the M. V. Lomonosov State University in Moscow. Beginning in the mid-1950s, Prokhorov concentrated on the development of masers and lasers and on the search for crystals with suitable spectral and relaxation properties. His detailed studies of ruby (one of the most useful crystals for lasers) led to its widespread use at microwave and optical wavelengths. Prokhorov also created paramagnetic masers and proposed the concepts of open resonators and gas dynamic lasers, and he further investigated the resonance and nonresonance interactions of laser radiation with matter. Prokhorov wrote a number of fundamental articles on the construction of infrared and visible light lasers and on nonlinear optics. Prokhorov died of pneumonia in Moscow in 2002. Prokhorov was honored on a stamp (Scott No. 2218j) issued by the island of St Vincent in 1995.

And then there was light

The race to make a laser began with Bell Laboratories. In the late 1950s the then Bell Telephone Laboratories was a well-funded research institute in Murray Hill, New Jersey, that already had a string of high-profile achievements to its name – including the transistor, which was invented in 1947 by John Bardeen, Walter Brattain and William Shockley. A few years later, a Bell Labs re search group led by Charles Townes proposed a device that could produce and amplify electromagnetic radiation in the microwave region of the spectrum. By 1953 the researchers had turned their theory into a working device, which they called a maser – an acronym for microwave amplification by stimulated emission of radiation. And in December 1958, Townes and his brother-in-law Arthur Schawlow wrote a famous paper (Physical Review 112 1940) describing how the maser concept could be extended into the optical regime, to make the first “infrared and optical maser” – in other words, a laser.