Line-width insensitive segmented wave reflectors having selected Bragg reflection characteristics

A segmented article is disclosed which has selected Bragg reflection characteristics for a selected input wavelength. The article includes alternating sections of optical materials which are aligned and have refractive indexes different from adjacent sections to form at least one superperiod consisting of a plurality of segments such that each segment consists of a section of a first optical material and a section of a second optical material. At least one segment of the superperiod is different in optical path from another segment of the superperiod, and the interfaces between sections of the superperiod create backward travelling waves of complex amplitude at the selected input wavelength. The sequentially odd interfaces in the superperiod form a first set of interfaces and the sequentially even interfaces in the superperiod form a second set of interfaces. The article is characterized by (1) the sum for the superperiod sections of the product of the length of each section in the direction of alignment and the refractive index of the section being equal to about Nz lambda /2 where Nz is an integer and lambda is the wavelength of an input wave; and (2) the interfaces of the sequentially odd or even set of interfaces in the superperiod being spaced such that the modulus of the sum of the complex amplitudes created by that set is about zero or is less than 40 percent of the modulus of the sum of the complex amplitudes created by the other set. Devices are disclosed where the Bragg reflection from a Bragg reflector of this invention is used to stabilize a laser source.