Chia-lung Tsai is currently pursuing Master’s in Optical Engineering from National United University, Taiwan.
It is an important phenomenon that homogeneous broadening effect makes the rare-earth-ion doped fiber amplifiers to have a broad and continuous gain bandwidth. The homogeneous broadening effect is widely observed at room temperature in isotropic glass materials and is highly dependent on the energy manifolds. The laser transition between two higher energy sublevels is usually corresponding to a shorter homogeneous broadening linewidth. This also implies that laser power variation coming from the impact of an adjacent wavelength is more alleviated at the shorter wavelength in gain bandwidth. The typical homogeneous broadening linewidth of a silica-based erbium-doped fiber laser is about 3-4 nm, 4-6 nm, and 6-8 nm, for the S-band (1450-1520 nm), C-band (1530-1560 nm), and L-band (1565-1610 nm) wavelengths, respectively. On the other hand, homogeneous broadening effect is also influential to the laser linewidth. However, it is not clear because the laser is normally happening at the gain peak wavelength without using a filter at a specific passband wavelength. In this work, we found that it is very interesting to investigate the homogeneous broadening effect at the short-wavelength edge of the gain boundary in erbium-doped fiber laser. In contrast to the conventional continuous wavelength tuning erbium fiber laser at C-band or L-band, the laser characteristics show very different behaviours to make the lasing wavelength splitting into multiple fine lines only at the extreme edge of the short-wavelength gain boundary and which has not yet been proposed. To achieve the lasing at the extreme short-wavelength gain boundary, an in-line fiber short-pass filter is incorporated into the erbium fiber laser ring cavity and the fundamental mode cutoff wavelength is thermally tuned to efficiently enforce the lasing moving toward the shortest end of the gain boundary to successfully reduce the homogeneous broadening effect to achieve multiple fine laser lines.
Kalmbach H E Gudrun, from 1967 to 1969, was a Lecturer and Research Assistant at the University of Illinois, Urbana. Then, she was an Assistant Professor at the University of Massachusetts, Amherst (1970–1971) and at the Pennsylvania State University (1969–1975). She habilitated in 1975 at the University of Ulm and worked as Professor from 1975 on. She initiated in mathematics the female issue since 1982, founded the Emmy-Noether Association for this and MINT. The invention, naming and organizing of MINT (Mathematik, Informatik, Naturwissenschaften, Technik) is due to her.
Dynamical geometries for octonian coordinates:\r\n\r\ne0 vector projections:\r\n1 Euclidean, spin\r\n2 spherical volume, entropy\r\n3 orbits of systems about a central axis\r\n4 rotated vector cone, whirl\r\n5 barycenter in volume, particle\r\n6 wave, frequency, world line of a system with momentum, p=mv\r\n7 cylindrical helix, light\r\n\r\nPhysical system: In mathematical terms, it is an object characterized by its properties; in physical terms it is a portion P of the physical world W chosen for analysis. \r\n\r\nWIGRIS Descriptions\r\n\r\n0 vectorial bifurcation to EM EM(pot) 1, GR E(pot) 5 (potentials, quarks); EM to E(magn) 4, E(heat) 2; GR to E(rot) 3, E(kin) 6; 2,3,4,6 to 8 gluons of SI, then heat chaos occurs.\r\n\r\nNotations: EM electromagnetism, magn magnetism, rot rotation, kin kinetic, Gleason measures as GF triples; spaces Rn (Cn) n-dimensional real (complex) space, Sn unit sphere in R(n+1), CPn complex projective space with coordinates; list of (pseudo) particles or vectors; energy E, interactions (EMI electromagnetic, GR gravity, SI strong, WI weak), integration or relativities (SR special, AG general relativity): \r\n1 123 GF, 1234 spacetime R4 linear Euclidean, weak bosons and spin, WI and EM, Hopf geometry with S3, EM charge \r\n2 246 GF, CP2 complex projective 2-dimensional for inner spaces of energy systems with boundary S2, spherical, phonon, heat, 1246, inner pressure, rgb-graviton\r\n3 347 GF, orbits and flat conic sections of a rotating system about an axis, angular momentum, 3457, GR cosmic speeds\r\n4 145 GF, light cone Minkowski metric SR, 1456 (with frequency/speed added), leptons, WI/SI coordinates in SR motion, speed inversion to dark energy\r\n5 257 GF, Schwarzschild radius and metric AG, Higgs boson and mass, GR, radius inversion for mass systems to dark matter\r\n6 365 GF, complex 3-dimensional SI space C3 123456 and S5, rotor, nucleon, gluon, 6 cooroll mill as SI 6 cycle for energy integrations, linear momentum \r\n7 176 GF, cylindrical helix geometry, rolled circle S1, atom, photon, EMI, functions exp(iφ) \r\n\r\nThere are three 4-dimensional subspaces: 1234 of spin (weak interaction and electromagnetism) – the WI/EM spacetime of physics, the light cone 1456 and the nuclear rotor 2356 of WIGRIS. Complex numbers are used for GF measures. In quantum mechanics, they are used for complex wave functions ψ; they are not observables, but only ψ ψ* as real probability distribution for their location in space. There are three characters of systems P shown in experiments: In measurements, they can behave like waves (6,7), they can behave like particles (1,5), and whirls (3,4) is added as a third character. For volumes with pressure of its inner energies, the heat equation adds entropy. The inner volumes (grids) arise as complex projective space CP2 from the SI space C3. Other spacetime grids belong to the Heisenberg uncertainties. The WIGRIS dynamics is a design which shows how nucleons inner energies develop and act for generating its experimentally verified properties. Newly added to quantum physical items are the GF for measurements, projective geometries and as group the Moebius transformations MT which contain the Pauli matrices, the Schwarzschild factor G matrix of order 6, the SR M matrix of order 2, the nucleon triangle symmetry D3 matrices. D3 and the conjugation operator C of physics generate a group of order 12, isomorphic to the one generated by G, M, for the two fermionic series of particles. \r\n