provides automatic alignment between the fibers and lasers in the y direction alignment in the z direction of a fiber to its corresponding laser in array chip 10 is accomplished by fixing the fiber core and the laser active region at the same height above the surface of the substrate 16 the position of a fiber in a v groove shown in a cross sectional view in fig3 is determined by the width w of the v groove and the diameter d of the fiber 125 u03bcm for conventional fibers the height of the core center above the substrate surface h core is given by the expression placement of the laser emitting region at a controlled height equal to h core above the substrate surface requires a new packaging approach conventional laser mounting techniques such as the use of eutectic preforms provide virtually no control over the thickness of the solder these soldering techniques will not be adequate to position the laser with the precision required which is approximately u00b1 1 u03bcm in the present invention the vertical position of each laser active region above the surface of the substrate is controlled by the use of a corrugated laser mounting pattern that is built into the substrate surface the.