THE BELL SYSTEM TECHNICAL JOURNAL DEVOTED TO THE SCIENTIFIC AND ENGINEERING ASPECTS OF ELECTRICAL COMMUNICATION Volume 48 September 1969 Number 7 Copyright 1969,American Telephone and Telegraph Company Integrated Optics:An Introduction By STEWART E.MILLER (Manuscript received January 29,1969) This paper oullines a proposal for a miniature form of laser beam circuitry.Index of refraction changes of the order of 10-or 10-in a substrate such as glass allow guided laser beams of width near 10 microns. Photolithographic technigues may permit simultaneous construction of complex circuit patterns.This paper also indicates possible miniature forms for a laser,modulator,and hybrids.If realized,this new art would facilitate isolating the laser circuit assembly from thermal,mechanical,and acoustic ambient changes through small overall size;economy should ultimately result. I.INTRODUCTION Laboratory work and experimental repeater work at laser wave- lengths (0.4 to 10 +um)has been carried out by interconnecting the oscillators,modulators,detectors,and so on,using a form of extremely short-range radio.A freely propagating beam has been reflected around corners,occasionally refocused with lenses to avoid energy loss resulting from beam spreading,and often sheltered by tubular enclosures from refractive distortions resulting from ther- mal gradients in the ambient air.Typical separations between com- ponents range from a few centimeters to a foot;aggregations of ap- paratus in a single-channel experimental laser repeater are measured 2059T H E BELL SYSTE M TECHNICA L JOURNA L DEVOTED TO THE SCIENTIFIC AND ENGINEERING ASPECTS OF ELECTRICAL COMMUNICATION Volume 48 Septembe r 1969 Numbe r 7 Copyright ® 1969, Amtrican Telephone and Telegraph Company Integrated Optics: An Introduction By STEWART E. MILLER (Manuecript received January 29, 1969) This paper outlines a proposal jor a mintcUure form of laser beam circuitry. Index of refraction changes of the order of 10" ' or 10"* in a substrate such as glass allow guided laser beam^ of width near 10 miarons. Photolitíwgraphic techniques may permit simultaneous construction of complex circuit patterns. This paper also indicates possible miniature forms for a laser, modulator, and hybrids. If realized, this new art vmdd facuitóte isolating the laser circuit assembly from thermal, mechanical, and acoustic ambient changes through small overall size; economy should ultimately result. I. INTRODUCTION Laboratory work and experimental repeater work at laser wave￾lengths (0.4 to 10 + μχη) has been carried out by interconnecting the oscillators, modulators, detectors, and so on, using a form of extremely short-range radio. A freely propagating beam has been reflected around comers, occasionally refocused with lenses to avoid energy loss resulting from beam spreading, and often sheltered by tubular enclosures from refractive distortions resulting from ther￾mal gradiente in the ambient air. Typical separations between com￾ponents range from a few centimeters to a foot; aggregations of ap ­ paratus in a single-channel experimental laser repeater are measured 2069