The excitation mechanism excitation mechanism
... with the gas molecules and transfer energy to them. Thus, the gas molecules are raised to excited state. Higher voltage is required to start the electrical discharge in the tube than to keep the discharge. Thus, a preliminary high voltage pulse is applied for initial discharge, and then the voltage ...
... with the gas molecules and transfer energy to them. Thus, the gas molecules are raised to excited state. Higher voltage is required to start the electrical discharge in the tube than to keep the discharge. Thus, a preliminary high voltage pulse is applied for initial discharge, and then the voltage ...
What is total internal reflection?
... • industrial applications (P.8) Science concepts. • photoelectric effect • mass-energy equivalence • radiation therapy ...
... • industrial applications (P.8) Science concepts. • photoelectric effect • mass-energy equivalence • radiation therapy ...
Defect-based Photonic Crystal Cavity for Silicon Laser PHYC/ECE 568
... Creating a defect into such a periodic lattice, can form states that can act as a waveguide or a localized state. The common feature of such defect modes is the tight localization of the optical mode to the defect and slab. This strong localization is favorable in nonlinear optics, because it helps ...
... Creating a defect into such a periodic lattice, can form states that can act as a waveguide or a localized state. The common feature of such defect modes is the tight localization of the optical mode to the defect and slab. This strong localization is favorable in nonlinear optics, because it helps ...
Creating laser light
... Armed with the concept of stimulated emission, we can sketch a simple picture of how a laser functions at the quantum level. First we must somehow attain a population inversion in the atoms of our laser medium. This requires enough energy to pump more atoms into the metastable state than there are i ...
... Armed with the concept of stimulated emission, we can sketch a simple picture of how a laser functions at the quantum level. First we must somehow attain a population inversion in the atoms of our laser medium. This requires enough energy to pump more atoms into the metastable state than there are i ...
LASERS How do they work?
... the condition required for stimulated emission to overcome absorption and so give rise to the amplification of light. In an assembly of chromium ions in which a population inversion has been set up, some will decay spontaneously to the ground state level emitting red light of wavelength 694.3 nm in ...
... the condition required for stimulated emission to overcome absorption and so give rise to the amplification of light. In an assembly of chromium ions in which a population inversion has been set up, some will decay spontaneously to the ground state level emitting red light of wavelength 694.3 nm in ...
Modern Physics Review
... solves the problem with the Rutherford-Bohr model. Explain how. 12. What is radioactivity and how does quantum mechanics explain it? 13. In the Rossi-Hall experiment, muons that have an extremely short half-life rain down on us from the upper atmosphere. Based on the short half-life, very few muons ...
... solves the problem with the Rutherford-Bohr model. Explain how. 12. What is radioactivity and how does quantum mechanics explain it? 13. In the Rossi-Hall experiment, muons that have an extremely short half-life rain down on us from the upper atmosphere. Based on the short half-life, very few muons ...
Photonic laser thruster
A photonic laser thruster is an amplified laser thruster that generates thrust directly from the laser photon momentum, rather than laser-heating propellant. The concept of single-bounce laser-pushed lightsails that utilize the photon momentum was first developed in the 1960s, however, its conversion of laser power to thrust is highly inefficient, thus has been considered impractical. Over 50 years, there had been numerous theoretical and experimental efforts to increase the conversion efficiency by recycling photons, bouncing them repetitively between two reflective mirrors in an empty optical cavity, without success. In December 2006, Young Bae successfully solved this problem and demonstrated the conversion efficiency enhancement by a factor of 100 and a photon thrust of 35 micronewtons by putting the laser energizing media between the two mirrors as in typical lasers, and the photonic laser thruster was born. In August 2015, the photonic laser thruster was demonstrated to increase the conversion efficiency enhancement by a factor over 1,000 and to achieve a photon thrust of 3.5 millinewtons at Y.K. Bae Corporation. In addition, Propelling, slowing and stopping of a small satellite, 1U CubeSat, in simulated zero-gravity were demonstrated. The photonic laser thruster was initially developed for use in nanometer precision spacecraft formation, for forming ultralarge space telescopes and radars. The photonic laser thruster is currently developed for high-precision and high-speed maneuver of small spacecraft, such as formation flying, orbit adjustments, drag compensation, and rendezvous and docking. The photonic laser thruster can be used for beaming thrust from a conventional heavy resource vehicle to a more expensive & lightweight mission vehicle, similar to tankers in aerial refueling.The practical usage of the photonic laser thruster for main space propulsion would require extremely high laser powers and overcoming technological challenges in achieving the laser power and fabricating the required optics. Photonic laser thrusters have a very high specific impulse, and can permit spacecraft reach much higher speeds than with conventional rockets, which are limited by the Tsiolkovsky rocket equation. If the photonic laser thruster is scalable for the use in such main space propulsion, multiple photonic laser thrusters can be used to construct a 'photonic railway' that has been proposed as a potential permanent transport infrastructure for interplanetary or interstellar commutes, allowing the transport craft themselves to carry very little fuel.