The effect of stitching errors on the spectral characteristics of DFB lasers fabricated using electron beam lithography

• Field stitching errors and their effect on the single-mode characteristics of distributed feedback (DFB) lasers fabricated using electron beam lithography were investigated. The stitching errors are associated with small-area, high-resolution electron beam exposure, which has the potential advantage of high-speed writing of laser gratings. Measurements show that the errors are composed of a systematic and a stochastic part. Their effect on the gain margin was simulated both for lambda;/4 phase-shifted and optimized multiple-phase-shifted DFB lasers. Simulations show that the lasers are insensitive to the systematic part of the stitching errors if the number of errors is large enough. The stochastic part was found to give rise to a variation in gain margin of the DFB lasers. It is concluded that the field stitching accuracy in the high-resolution mode of a commercial system for electron beam lithography is sufficient to provide a high yield of single-mode lasers. However, it is essential that certain precautions be taken considering exposure conditions and that a fault tolerant laser design be used

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Telekommunikation (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Telecommunications (hsv//eng)

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

Nyckelord

Bragg grating;DFB lasers;InP-InGaAsP laser;electron beam lithography;fault tolerant laser design;gain margin;high-resolution electron beam exposure;high-speed writing;laser gratings;phase shifted lasers;simulation;single-mode characteristics;spectral characteristics;stitching errors;stochastic errors;systematic errors;III-V semiconductors;diffraction gratings;distributed feedback lasers;electron beam lithography;errors;gallium arsenide;gallium compounds;indium compounds;optical workshop techniques;semiconductor lasers

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)