A key element in the generation of optical torque in optical traps, which occurs when electromagnetic angular momentum is transferred from the trapping beam to the trapped particle by scattering, is the symmetries of the scattering particle and the trapping beam. We discuss the effect of such symmetries on the generation and measurement of optical torque in optical tweezers, and some consequent...

1. Introduction The key part of the optical network module that we are proposingg1],2] is a two dimensional optical element consisted of the vertical cavity surface-emitting laser (VCSEL) arrays and the switching devices with optical lter. In this paper, we report on a study of the fabrication technologies of a distributed Bragg reeector (DBR) for VCSEL and optical lter for the switching device...

III. Preliminary results 5 IIIa. Three-mirror quasi-optical passive compressor 6 IIIb. Optimization of the three-mirror passive compressor parameters 7 IIIc. Prototype of a passive compressor with a three-mirror resonator 10 IIId. Four-mirror quasi-optical passive compressor 14 IIIe. Prototype of a passive compressor with a four mirror resonator 15 IIIf. Diffraction gratings as active elements ...