Generation of propagation-invariant light beams from semiconductor light sources

We have studied the possibility of generating propagation-invariant (nondiffracting) light beams using various semiconductor sources of radiation. The propagation-invariant (Bessel) beams have been generated using cone-shaped lenses (axicones) with an apical angle of 178A degrees and 170A degrees, which provided beams with a central spot diameter of 100 and 10 mu m, respectively. The radiation sources were represented by various types of light-emitting diodes, quasi-single-mode semiconductor vertical-cavity surface-emitting lasers and broad-stripe (100 mu m) edge-emitting laser diodes. It is demonstrated that these semiconductor light sources offer a promising basis for the generation of propagation-invariant light beams in various devices (including optical tweezers) intended for manipulating micro- and nanodimensional objects.