Browse Prior Art Database

Fabrication of Lenses on Tips of Fibers

IP.com Disclosure Number: IPCOM000088975D
Original Publication Date: 1977-Aug-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Crow, JD: AUTHOR [+2]

Abstract

An optical fiber tip having a clean flat end surface is progressively inserted into a glass etchant solution in a time-depth controlled sequence in order to etch the cladding and core at the fiber tip into a controlled contour. The tip is then flame-smoothed to decrease scattering losses.

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Fabrication of Lenses on Tips of Fibers

An optical fiber tip having a clean flat end surface is progressively inserted into a glass etchant solution in a time-depth controlled sequence in order to etch the cladding and core at the fiber tip into a controlled contour. The tip is then flame-smoothed to decrease scattering losses.

The present method does not require any photolithography on small diameter surfaces and may be used with any glass composition for the core and cladding. It requires only simple equipment, and the actual resulting tip shape and radius of curvature may be controlled.

The fiber is first broken to form a clean flat end surface by any known technique (Fig. 1). The tip is then progressively inserted into a bath of glass etchant solution (e.g., dilute HF) following a controlled depth-versus-time sequence in order to etch the tip into a controlled contour. Figs. 2-4 illustrate a simple idealized time-depth schedule where the fiber depth is increased in step increments to make a staircase contour. More elaborate continuously varying time-depth sequences would produce smoother profiles. The miniscus on the etchant solution also smooths the profile. Furthermore, vapors from etchant solutions, such as HF, also cause etching above the liquid surface, which nay be used to produce a tapered profile above the liquid surface even without a depth change. Fig. 5 shows a resulting flame-smoothed linear contour with rounded tip.

The process may be used to pro...