Low-loss two-channel fiber-optic waveguide

Abstract

In a recent paper (Temperley and Trevena 1977) it was suggested that metastable effects in liquids, such as tensile strength and superheating, should be interpreted in ternis of a truncated virial series. A review of the experimental evidence showed that there is reasonable agreement between theoretical and experimental results on tensile strength with the exceptions of ultrasonic methods and 'once only' dynamical methods involving reflection of a pressure pulse at a free surface.Evidence is now brought forward to show that the reflection of even a small amplitude pressure pulse at a free surface is accompanied by considerable distortion. An explanation of this fact, and of the low values of tensile strength of water inferred from underwater explosion and similar 'once only' pulses, is suggested in the light of existing ideas about the structure of a liquid surface.It is concluded that there is now no real disagreement between experiment and theory on tensile strength as there are now acceptable explanation? of the low values found from ultrasonic and 'once only' pulse methods.

Single-mode fibers with an additional ring lightguide for two-channel data transmission

“…3 The normalized mode power, propagating in the ring layer of thickness a3-a2 = 1 5 tm, is the core-to-ring crosstalk acr. The later value strongly depends on a2 (see Fig.3.).…”

“…Cladding, 125 pm For cylindrical fiber geometry, the field components Er, E+, Hr, H are expressed through E and H [3]. The longitudinal field components in the core and in the ring are E1=A1J1(k1r)+B1N(kr) H1CJ(k1r)+D1N,,(k1r), where J and N,, are the Bessel functions ofthe first and second kind, respectively, k2ko2(n2-n92)>O is the squared wavenumber ofthe mode in the i-th layer ofthe fiber, k0=2ii/2.…”