Light-induced gaps in semiconductor band-to-band transitions

We observe a triplet around the third harmonic of the semiconductor band gap when exciting 50-100 nm thin GaAs films with 5 fs pulses at 3 x 10(12) W/cm(2). The comparison with solutions of the semiconductor Bloch equations allows us to interpret the observed peak structure as being due to a two-band Mollow triplet. This triplet in the optical spectrum is a result of light-induced gaps in the band structure, which arise from coherent band mixing. The theory is formulated for full tight-binding bands and uses no rotating-wave approximation.     

A note on the solution of bilinear programming problems by reduction to concave minimization

We present a new algorithm for solving the bilinear programming problem by reduction to concave minimization. This algorithm is finite, does not assume the boundedness of the constraint set, and uses an efficient procedure for checking whether a concave function is bounded below on a given halfline. Some preliminary computational experience with a computer code for implementing the algorithm on a microcomputer is also reported.