High-quality porous-silicon buried waveguides

Abstract

This letter reports a method to produce porous-silicon waveguides by means of a laser local oxidation process. The estimated losses of the waveguides are below 1 dB/cm. This demonstrates the applicability of this material in integrated optics and telecommunications. Moreover, our results disclose the opportunity to integrate optoelectronic devices onto Si substrates. The laser writing method is achievable at low laser power, thus it is highly efficient and achievable with the standard equipment present in most laboratories. Another advantage is that oxidation is achieved without heating the complete chip, thus simplifying the integration process, i.e., the oxidation is inherently local through the direct-write process. This method opens the opportunity to build microstructures, like channel and membrane filters, in a flexible manner by R&D laboratories.

Nanocrystalline Porous Silicon

“…For that purpose substituting surface hydrogen by another chemical species has appeared desirable. Oxidations (Rossi et al, 2001;Bsiesy, et al 1991;Petrova-Koch et al, 1992) nitradation (Anderson et al, 1993) and halogenetion (Lauerhaas & Sailor, 1993) are found to be useful for PS surface passivation. Derivatisation by organic groups and polymer (Lees et al 2003;Mandal et al 2006), offers an alternative possibility to stabilize the material.…”

Prospects for a waveguide Raman amplifier in porous silicon at 1.5 μm

“…First of all, even if the result regarding the losses reported in Ref. [12] are impressive, the realisation of porous silicon waveguide having low losses is still a difficult task. Moreover, regarding the nonlinear optical characterization, the high pump power needed to excite nonlinear effects could damage the porous silicon.…”

“…[12], a method for the lateral definition of waveguide was presented based on laser local oxidation (LALOX). This approach demonstrated a simple and efficient way to realize buried waveguides.…”

Laser-written nanoporous silicon diffraction gratings for biosensors

“…The PS sample is placed on a 2D motorized stage driven by a computer, any pattern can be in principle produced. The laser direct writing process is the same as that was reported for the fabrication of nanoporous silicon waveguides [15]. Gratings with periods ranging from 3 to 7 µm were fabricated by using a continuous wave argon ion laser at the power up to 20 mW and a laser scanning speed up to 400 µm/s.…”