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Published in Philip A. Laplante, Comprehensive Dictionary of Electrical Engineering, 2018
optical resonator binary numbers 0 and 1 with dark and bright states or low and high intensity, respectively. However, some difficulty would occur when 1 has to be the output from 0, because no energy can be generated for 1 from 0 without pumping light. Binary numbers 0 and 1 can be represented by a coded pattern instead of the intensity of a single spot. They can also be represented by two orthogonal polarizations, although the final states should be converted to intensity, which is the only parameter that can be detected by a detector. optical resonator electromagnetic cavity designed to have low loss at optical frequencies. optical signal processing the use of light with optical devices to process signals and images, exploiting the high bandwidths and inherent parallelism offered by optical systems. optical soliton a pulse that propagates without change in shape through a dispersive nonlinear optical medium as a consequence of an exact balance between dispersive and nonlinear effects. The propagation of such a pulse is described by the nonlinear Schrüdinger equation. o optical switching a process in which one optical beam is controlled by another optical wave or by an electro-optical signal. optical tensor-matrix multiplication an operation performing tensor-matrix multiplication using optical devices. For tensor W and matrix X , the tensor-matrix multiplication produces matrix Y , whose elements are y11 = w 1111 x11 + w 1112 x12 + w 1211 x21 + w 1212 x22 y12 = w 1121 x11 + w 1122 x12 + w 1221 x21 + w 1222 x22 y21 = w 2111 x11 + w 2112 x12 + w 2211 x21 + w 2212 x22 y22 = w 2121 x11 + w 2122 x12 + w 2221 x12 + w 2222 x22 An incoherent optical processor can implement this operation as follows. The two-by-two 0 matrix x11 x21 x12 x22
Black-body Radiation, Einstein and Planck's Law
Published in Caio Lima Firme, Quantum Mechanics, 2022
Where E and B are the electric and magnetic field vectors, ε0 is the vacuum permittivity and μ0, is the vacuum permeability. The electromagnetic cavity is an empty container for the fields wave function inside.
Photon bursts at lasing onset and modelling issues in micro-VCSELs
Published in Journal of Modern Optics, 2020
T. Wang, G. P. Puccioni, G. L. Lippi
The fully stochastic approach rests on the definition of the interaction processes as discrete recurrence relations where a probability of occurrence is assigned to each event with Poisson statistics. Calling M the number of excited emitters, s the number of photons (present in the lasing mode) which stem from a stimulated emission process, r the photons on-axis (lasing mode) whose origin is a spontaneous relaxation and all other photons spontaneously emitted into all other electromagnetic cavity modes, we end up with the following recurrence relations (31): where represents the pumping process (proportional to the pump rate), the spontaneous relaxation processes, which reduce the population inversion M, with branching into the lasing mode (represented by ) or into all other electromagnetic cavity modes (collectively represented by ), stands for the stimulated emission process which, proportional to the product of and , depletes M, and account for the leakage through the output coupler of stimulated and on-axis spontaneous photons – respectively – probabilistically described through the photon lifetime , and describes the seeding process which starts the first stimulated emission process, as explained in detail in Section 5. represents the losses for the off-axis fraction of the spontaneous photons (laterally) exiting the cavity volume with lifetime , similarly to . All processes are probabilistic and follow Poisson statistics.