A planar, single-transverse-mode waveguide laser has been fabricated in erbium-ytterbium codoped silicate glass using potassium ion exchange. The laser operates at 1536.8nm, has a slope efficiency of 5.5%, and exhibits a launched pump power threshold of 14.8mW when pumped at 966.6~11. Introduction: Er3+:Yb3+ codoping has become an effective method for producing short, efficient lasers and amplifiers in the long haul telecommunications wavelength range. Ytterbium codoping increases the pump absorption near 980nm and efficient energy transfer between the Yb'' and the Er3+ ions enables the operation of centimetre long lasers with low Er" concentrations. This mechanism was first demonstrated by Snitzer and Woodcock in hulk glass [I]. More recently, Er3+:Yb3+ codoped fibre lasers [2, 31 and planar waveguide amplifiers [4] have been demonstrated. Ion exchange is a well known method for fabricating integrated optic devices in glass [5]. Ion exchanged devices are inexpensive, robust, and fibre compatible. Monomode planar waveguides lasers have been successfully fabricated in Er3+doped BK-7 glass [6]. The key to this demonstration was the introduction of rare-earth dopants into an ion exchangeable glass host. We report a short, planar Er3+:Yb3+ waveguide laser fabricated by ion exchange.
Correlation of atomic force microscopy sidewall roughness measurements with scanning electron microscopy line-edge roughness measurements on chemically amplified resists exposed by x-ray lithography
Low-stress sputtered chromium-nitride hardmasks for x-ray mask fabrication Refractory x-ray masks for a wide variety of pattern types were fabricated using tantalum silicon as the absorber material. Both positive ͑Shipley UVIII®͒ and negative ͑Shipley SNR200®͒ chemically amplified electron beam resists were exposed and the patterns transferred into a silicon oxynitride hardmask. The amorphous TaSi absorber was then etched using a Cl 2 /O 2 reactive ion etch ͑RIE͒. From a mask manufacturing standpoint, the challenge is etching the wide variety of feature types that commonly occur in device processing. The overall etch process was characterized for the formation of both freestanding lines ͑using negative electron beam resist͒ and narrow trenches ͑using positive resist͒. RIE lag, feature shape dependence, and cross-mask uniformity in the etch bias were characterized for feature sizes down to 125 nm. The etch process has been implemented in a pilot line environment and is being used to produce product masks.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.