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Dear Vipul, I've included two figures to describe the integral ratio which I cannot describe as easily in text format (figure 1.jpg and Figure 2.jpg). Figure 1 Figure 2 In Figure 1, Ex is the electrical field intensity of the first transverse mode (TE) propagating in the active region. In other words, this formula defines the fraction of the mode energy which is confined to the active layer and thus “sees” optical gain. In practice, only the fundamental transverse mode lases. It is also found experimentally that its polarization is almost invariably TE. For these reasons, one is mostly concerned with the propagating characteristics of the TE mode in a symmetrical slab guide. A more general approximate solution for that is valid is found by Botez*. Botez’s* analytical techniques yield accurate results in calculating for 3-region guides. The approximation given by Botez* for calculating the optical confinement factor in a symmetrical waveguide for the TE mode is found in Figure 2 Here, lambda is the vacuum wavelength at the lasing photon energy, D is the normalized thickness of the active region, n(r,w) and n(r,c) are the indices of refraction of the active and cladding layers, respectively, and w is the thickness of the active layer. Hope this helps! ---* Dr. Ken Beck ------------------------------------------------------------------- * D. Botez, “Analytical approximation of the radiation confinement factor for the TE0 mode of a double heterojunction laser,” IEEE J. Quantum Electron., vol. QE-14, pp. 230–232, 1978. D. Botez, “Near and far-field analytical approximations for the fundamental mode in symmetrical waveguide DH lasers,” RCA Rev., vol. 39, pp. 577–603, 1978.

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