Mode locking is a technique in optics by which a laser can be made to produce pulses of light of extremely short duration, on the order of picoseconds (10−12 s) or femtoseconds (10−15 s). A laser operated in this way is sometimes referred to as a femtosecond laser, for example, in modern refractive surgery. The basis of the technique is to induce a fixed phase relationship between the longitudinal modes of the laser's resonant cavity. Constructive interference between these modes can cause the laser light to be produced as a train of pulses. The laser is then said to be "phase-locked" or "mode-locked".
Nicolaas Bloembergen was a Dutch-American physicist and Nobel laureate, recognized for his work in developing driving principles behind nonlinear optics for laser spectroscopy. During his career, he was a professor at Harvard University and later at the University of Arizona and at Leiden University in 1973.
Ti:sapphire lasers (also known as Ti:Al2O3 lasers, titanium-sapphire lasers, or Ti:sapphs) are tunable lasers which emit red and near-infrared light in the range from 650 to 1100 nanometers. These lasers are mainly used in scientific research because of their tunability and their ability to generate ultrashort pulses thanks to its broad light emission spectrum. Lasers based on Ti:sapphire were first constructed and invented in June 1982 by Peter Moulton at the MIT Lincoln Laboratory.
In optics, an ultrashort pulse, also known as an ultrafast event, is an electromagnetic pulse whose time duration is of the order of a picosecond or less. Such pulses have a broadband optical spectrum, and can be created by mode-locked oscillators. Amplification of ultrashort pulses almost always requires the technique of chirped pulse amplification, in order to avoid damage to the gain medium of the amplifier.
In physics, terahertz time-domain spectroscopy (THz-TDS) is a spectroscopic technique in which the properties of matter are probed with short pulses of terahertz radiation. The generation and detection scheme is sensitive to the sample's effect on both the amplitude and the phase of the terahertz radiation.
Chirped pulse amplification (CPA) is a technique for amplifying an ultrashort laser pulse up to the petawatt level, with the laser pulse being stretched out temporally and spectrally, then amplified, and then compressed again. The stretching and compression uses devices that ensure that the different color components of the pulse travel different distances.
In optics, femtosecond pulse shaping refers to manipulations with temporal profile of an ultrashort laser pulse. Pulse shaping can be used to shorten/elongate the duration of optical pulse, or to generate complex pulses.
Multiphoton intrapulse interference phase scan (MIIPS) is a method used in ultrashort laser technology that simultaneously measures, and compensates femtosecond laser pulses using an adaptive pulse shaper. When an ultrashort laser pulse reaches a duration of less than a few hundred femtosecond, it becomes critical to characterize its duration, its temporal intensity curve, or its electric field as a function of time. Classical photodetectors measuring the intensity of light are still too slow to allow for a direct measurement, even with the fastest photodiodes or streak cameras.
An ultrashort pulse laser is a laser that emits ultrashort pulses of light, generally of the order of femtoseconds to one picosecond. They are also known as ultrafast lasers owing to the speed at which pulses "turn on" and "off"—not to be confused with the speed at which light propagates, which is determined by the properties of the medium, particularly its index of refraction, and can vary as a function of field intensity and wavelength.
Cross-polarized wave (XPW) generation is a nonlinear optical process that can be classified in the group of frequency degenerate processes. It can take place only in media with anisotropy of third-order nonlinearity. As a result of such nonlinear optical interaction at the output of the nonlinear crystal, it is generated a new linearly polarized wave at the same frequency, but with polarization oriented perpendicularly to the polarization of input wave
Eric Van Stryland was president of the Optical Society of America in 2005.
Erich P. Ippen is a principal investigator in the Research Laboratory of Electronics (RLE) at the Massachusetts Institute of Technology (MIT). He holds appointments as the Elihu Thomson Professor of Electrical Engineering Emeritus and Professor of Physics Emeritus. He is one of the leaders of RLE’s Optics and Quantum Electronics Group.
Yuen-Ron Shen is a Taiwanese physicist. He is a professor emeritus of physics at the University of California, Berkeley, known for his work on non-linear optics. He was born in Shanghai and graduated from National Taiwan University. He received his Ph.D. in Applied Physics from Harvard under physicist and Nobel Laureate Nicolaas Bloembergen in 1963, and joined the department of physics at Berkeley in 1964. In the early years, Shen was probably best known for his work on self-focusing and filament propagation of laser beams in materials. These fundamental studies enabled the creation of ultrafast supercontinuum light sources. In the 1970s and 1980s, he collaborated with Yuan T. Lee on the study of multiphoton dissociation of molecular clusters. The molecular-beam photofragmentation translational spectroscopy that they developed has clarified much of the initial confusion concerning the dynamics of infrared multiphoton dissociation processes. In the 1980s and 1990s, Shen developed various nonlinear optics methods for the study of material surfaces and interfaces. Among these techniques, second-harmonic generation and sum frequency generation spectroscopy are best known and now widely used by scientists from various fields. He has collaborated with Gabor Somorjai on the use of the technique of Sum Frequency Generation Spectroscopy to study catalyst surfaces. He is the author of the book The Principles of Nonlinear Optics. Shen belongs to the prolific J. J. Thomson academic lineage tree. Currently, Shen works in U. C. Berkeley and Fudan University in Shanghai.
Pulsed operation of lasers refers to any laser not classified as continuous wave, so that the optical power appears in pulses of some duration at some repetition rate. This encompasses a wide range of technologies addressing a number of different motivations. Some lasers are pulsed simply because they cannot be run in continuous mode.
Cho Minhaeng is a South Korean scientist in researching physical chemistry, spectroscopy, and microscopy. He was director of the National Creative Research Initiative Center for Coherent Multidimensional Spectroscopy and is founding director of the Center for Molecular Spectroscopy and Dynamics in the Institute for Basic Science (IBS), located in Korea University.
High Harmonic Generation (HHG) is a non-perturbative and extremely nonlinear optical process taking place when a highly intense ultrashort laser pulse undergoes an interaction with a nonlinear media. A typical high order harmonic spectra contains frequency combs separated by twice the laser frequency. HHG is an excellent table top source of highly coherent extreme ultraviolet and soft X-ray laser pulses.
Miro Erkintalo is a New Zealand physicist specialising in nonlinear optics and laser physics, based at the University of Auckland.
Debabrata Goswami FInstP FRSC, is an Indian chemist and the Prof. S. Sampath Chair Professor of Chemistry, at the Indian Institute of Technology Kanpur. He is also a professor of The Department of Chemistry and The Center for Lasers & Photonics at the same Institute. Goswami is an associate editor of the open-access journal Science Advances. He is also an Academic Editor for PLOS One and PeerJ Chemistry. He has contributed to the theory of Quantum Computing as well as nonlinear optical spectroscopy. His work is documented in more than 200 research publications. He is an elected Fellow of the Royal Society of Chemistry, Fellow of the Institute of Physics, the SPIE, and The Optical Society. He is also a Senior Member of the IEEE, has been awarded a Swarnajayanti Fellowship for Chemical Sciences, and has held a Wellcome Trust Senior Research Fellowship. He is the third Indian to be awarded the International Commission for Optics Galileo Galilei Medal for excellence in optics.
János Hebling is a Hungarian physicist, known for his preliminary works at Terahertz physics and spectroscopy. He was born at Zirc on 9 May 1954 and currently works as a professor at the Institute of Physics at University of Pécs and is an active researcher at the Hungarian Academy of Sciences and ELI.
Alexander Luis Gaeta is an American physicist and the David M. Rickey Professor of Applied Physics at Columbia University. He is known for his work on quantum and nonlinear photonics. He is a Fellow of the American Physical Society, Optica, and of the Institute of Electrical and Electronics Engineers.
