<title>Phase locking of 2D structures</title>

Abstract

The overview of the phase-locking technique is presented. Analysis of the parameters that influence on the phaselocking is given. Admissible range of the deviation of the linear laser diode array, external cavity parameters is estimated. Comparison of the external Talbot cavity configuration with the other ones is held. Attention is paid to both investigation and employment of the laser diode arrays consisting of wide aperture lasers that opens an avenue to high power output radiation in a phase-locked mode. Special consideration is given to the cavity supermodes selection.Our experiments both confirm actual feasibility of 1D and 2D phase-locking of LDA's with specified parameters in the external Talbot (LC=ZT/4) cavity and illustrate theoretical predictions ofthe system stability and selectivity, so that:. phase-locking in 1D configuration allowed difractional limited lobes width W=O.5 mrad;. tiltingof the output mirror provided "in-phase" supermode selection;. phase-locking in 2D configuration of the two LDA's of N=8 lasers, separated by 1600 mkm resulted in diffractional lobes full width at halfmaximum '=O.5 mrad in slow axis and 8'3!=O.25 mrad in fast axis.

High-Power Optics

“…According to the results of modelling intracavity optical systems [78][79][80][81][82][83][84][85][86], the use of adaptive POEs allows one to obtain the diffraction angular divergence of radiation fluxes when use is made of unstable resonators in high-power carbon dioxide laser systems. Adaptive POEs were essentially a new type of devices ensuring the local control of phase characteristics of coherent radiation fluxes.…”

“…In this part of the review we present the results of the studies on the creation of phase correctors of the beam path for laser systems based on POEs being cooled [79][80][81][82][83][84][85][86]. The shape of the reflecting surface is controlled in this case by the deformation of the porous structure of the heat exchanger.…”

“…This method is simple to implement and is widely used when creating precise adaptive POEs for highpower lasers and astronomical telescopes. At present, adaptive POEs of mirror type were created with an aperture diameter of one meter and the number of control channels (i.e., the number of actuators) up to several hundreds [75][76][77][78][79][80][81][82][83][84][85]. The study of adaptive POEs showed the versatility and high efficiency of this method for obtaining aberration-free fluxes of coherent radiation.…”

High power optics and its new manifestations

“…Third, and in our opinion, the most promising line of laser diode assemblies is the creation of a phase-locked diode array [46][47][48][49][50][51][52][53][54]. The output radiation of such a laser is a set of narrowly focused interference peaks (in particular one peak) with a small divergence.…”