RESUMEN
The theory, production process, and properties of wavelength division multiplexers (WDM) designed on the beam splitting principle are described. Typically these modules require no lenses, and the edge interference filter applied to the oblique polished single-mode or multimode fiber end face exhibits only minimal polarizing effects. Whereas all the fibers of multimode modules are identical in type, single-mode modules require a large-diameter core fiber for coupling out light. The characteristics of the couplers depend on the given type of fiber (single-mode or multimode), the light sources (laser diodes or LEDs), the channel separation, and the channel used (transmission or reflection). Insertion losses vary between 0.7 and 2 dB, far-end cross talk attenuation varies between 11 and 22 dB, and near-end cross talk attenuation exceeds 40 dB.
RESUMEN
In a rotational ellipsoidal exfocal pumping system the linear lamp is arranged between vertex and nearest focus, and the laser rod is aligned between the second focus and the other vertex along the major axis of a rotational ellipsoidal mirror. For this optical pumping system, a calculation of the pump light distribution in the laser rod was performed on a computer by use of a ray tracing procedure. The calculations take account of reflection losses, multiple reflections, and shadowing at the end faces of the laser rod and the lamp. A series of diagrams presents the results of the computer calculations, which are also compared with experimental results.
RESUMEN
Periodic resonant reflectors consisting of a periodic succession of equally spaced, uncoated, identical, optical plates are analyzed both by a matrix method known from thin film theory and by conventional electrical theory of cascaded two-ports. Simple formulas are derived for the design of resonant reflectors according to given specifications. As an example the resulting formulas are applied to design a periodic resonant reflector for a ruby laser.