The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 31, 2000
Filed:
Feb. 19, 1999
Ivan Avrutsky, Warren, MI (US);
Hanan Anis, Kanata, CA;
Toshi Makino, Nepean, CA;
Jingming Xu, Oakville, CA;
Northern Telecom Limited, Montreal, CA;
Abstract
A superimposed grating tunable WDM semiconductor laser is provided comprising a grating structure is a binary superimposed grating comprising a plurality of segments of equal dimension, s, each segment having one of two values of refractive index, whereby the grating structure is provided by a binary modulation of the refractive index modulation of segments s along the length of the grating. Thus, for a superimposed grating structure for an optoelectronic device for providing a spectrum comprising j reflection peaks at wavelengths .lambda..sub.j, the grating comprising a binary superimposed grating (BSG) having a sequence of a plurality of segments of equal size s, each segment of the sequence having a refractive index of one of two values wherein the effective waveguide index of the ith segment n.sub.i.sup.0 (.lambda.) is allowed to be changed by .DELTA.n.multidot.(m-1/2) with m=1 or m=0: ##EQU1## where i=1,2,3 . . . is the segment number, for digital position i.multidot.s, n.sup.0 (.lambda.) is a waveguide effective index, including both waveguide and material dispersion, and the function f(x) is a weighted sum of sinusoidal functions of desirable period .LAMBDA..sub.j ##EQU2## and, periods .LAMBDA..sub.j relate to the spectral positions of reflection peaks .lambda..sub.j through the waveguide index n.sup.0 (.lambda.)