The aim of this study is to develop a novel composite system which employs a biomimetic approach to perform a self-repairing function. Such a system can perform two functions; the visual enhancement of impact damage by the bleeding action of a highly conspicuous medium such as fluorescent dye, and the restoration of mechanical properties by a healing agent, stored within hollow fibres, infiltrating the damaged area and acting to ameliorate the effect of the damage. Impact indentation followed by four-point bend flexural testing was conducted to evaluate the strength restoration after self-repair. The results of mechanical testing have shown that a significant fraction (∼97%) of strength is restored by the self-repairing effect.

‘Bleeding composites’—damage detection and self-repair using a biomimetic approach

After a brief review of early lightguide work, the authors assess advances since the mid-1970s. They note important work on strength distributions and procedures for improving strength. This is followed by a discussion of long-length strength, prooftesting and splicing. Flaw character is studied along with strength degradation, fatigue limits, aging and fatigue, and hermetic coatings. >

Strength and fatigue of silica optical fibers

The use of laser scanning techniques for acquisition and printing of images is reviewed with primary emphasis on the printing application. Following an introduction to the basic configuration of laser scanners and to the terminology of this field, some of the principal characteristics of these scanners are summarized. A short overview is given of the key components of scanners, i.e., lasers, modulators, and light deflectors. The integration of these and other components into complete scanning systems is then described, including discussion of optical design issues and several examples of practical optical system design for polygon scanners. Holographic scanners and some of their design considerations are discussed. The electronic and mechanical techniques required for satisfactory scanner design and construction are described. Finally, the embodiment of various design approaches into practical scanners is illustrated by a survey of some existing printer products.

Laser scanning for electronic printing

An optical fiber formed from a glass preform substantially free of OH impurities is disclosed. The optical fiber is made to be free of OH impurities by a method having the steps of introducing a moving stream of vapor mixture including at least one compound glass-forming precursor together with an oxidizing medium into a tube, while generating a hydrogen-fee isothermal plasma on an outer surface of the tube to react the mixture and produce a glassy deposit on an inner surface of the tube. The glass preform is drawn to produce the optical fiber.

Optical fiber with low OH impurity and communication system using the optical fiber

Stochastic programming models of optical fiber production planning are presented. The purpose is to set the optimal fiber manufacturing goals while accounting for the uncertainty primarily in the yield and secondly in the demand. The model is solved for the case when the data follows a multivariate discrete distribution, and also for the case of a multivariate normal distribution, which is used to approximate the discrete data.

Solution of a Product Substitution Problem Using Stochastic Programming

The cost of fiber has been steadily decreasing because of the experience learned in production and developments in fiber processing. In this paper we will review the processes for making optical fibers, dwelling mostly on the fiber drawing process. Our results show that the fiber draw rate has been increased to more than 10 m/s without any degradation in fiber performance and specifications. The technology is not fully mature and it is likely that even higher rates should be achievable.

Optical fiber manufacturing techniques

An X-Y galvanometer deflection system capable of high precision in a random access mode of operation is described. Beam positional information in digitized form is obtained by employing a Ronchi grating with a sophisticated optical detection scheme. This information is used in a control interface to locate the beam to the required precision. The system is characterized by high accuracy at maximum speed and is designed for operation in a variable environment, with particular attention placed on thermal insensitivity.

Galvanometer deflection: a precision high-speed system

An improved interferometer for monitoring Rayleigh waves is described. Consisting of a light source, reflective grating, lens, and detector, the design is simple and inexpensive. It can be employed with specular as well as diffuse reflecting surfaces to monitor surface deformations with the sensitivity of a Michelson interferometer. By spinning the grating element, sensitivity variations with grating position are removed, resulting in stable operation. The interferometer response does vary with acoustic wavelength; a discussion of acoustic bandwidth shows that proper design can result in either a wide or narrow bandwidth response.

Donald P. Jablonowski

Papers

Optical fiber manufacturing techniques

Galvanometer deflection: a precision high-speed system

Simple interferometer for monitoring Rayleigh waves.