Search results
Results from the WOW.Com Content Network
The carbon-dioxide laser (CO2 laser) was one of the earliest gas lasers to be developed. It was invented by Kumar Patel of Bell Labs in 1964 [1] and is still one of the most useful types of laser. Carbon-dioxide lasers are the highest-power continuous-wave lasers that are currently available. They are also quite efficient: the ratio of output ...
Mode locking. 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.
Another very important mode is the G mode (G from graphite). This mode corresponds to planar vibrations of carbon atoms and is present in most graphite-like materials. [8] G band in SWNT is shifted to lower frequencies relative to graphite (1580 cm −1) and is split into several peaks. The splitting pattern and intensity depend on the tube ...
In CO 2, the bending vibration ν 2 (667 cm −1) has symmetry Π u.The first excited state of ν 2 is denoted 01 1 0 (no excitation in the ν 1 mode (symmetric stretch), one quantum of excitation in the ν 2 bending mode with angular momentum about the molecular axis equal to ±1, no excitation in the ν 3 mode (asymmetric stretch)) and clearly transforms according to the irreducible ...
Infrared spectroscopy (IR spectroscopy or vibrational spectroscopy) is the measurement of the interaction of infrared radiation with matter by absorption, emission, or reflection. It is used to study and identify chemical substances or functional groups in solid, liquid, or gaseous forms. It can be used to characterize new materials or identify ...
Coupled mode theory (CMT) is a perturbational approach for analyzing the coupling of vibrational systems (mechanical, optical, electrical, etc.) in space or in time. Coupled mode theory allows a wide range of devices and systems to be modeled as one or more coupled resonators. In optics, such systems include laser cavities, photonic crystal ...
Scattering. In physics, Raman scattering or the Raman effect (/ ˈrɑːmən /) is the inelastic scattering of photons by matter, meaning that there is both an exchange of energy and a change in the light's direction. Typically this effect involves vibrational energy being gained by a molecule as incident photons from a visible laser are shifted ...
Without an etalon, a laser will generally produce light over a wavelength range corresponding to a number of cavity modes, which are similar to Fabry–Pérot modes. Inserting an etalon into the laser cavity, with well-chosen finesse and free-spectral range, can suppress all cavity modes except for one, thus changing the operation of the laser ...