Optical gain in Si/SiO2 lattice: Experimental evidence with nanosecond pulses

Experimental evidence of population inversion and amplified spontaneous emission was found for Si nanocrystallites embedded in ${\mathrm{SiO}}_{\mathrm{2}}$ surrounding under pumping with 5 ns light pulses at 380, 400, and 500 nm. As an important property, our experiments show a short lifetime of the population inversion allowing a generation of short (a few nanosecond) amplified light pulses in the ${\mathrm{Si/SiO}}_{\mathrm{2}}$ lattice. The estimate for optical gain in the present samples is 6 cm⁻¹ at 720 nm.