ABSTRACT
Experimental results on 1D and 2D phase-locking of laser diode arrays are presented. Attention is paid to the employment of the arrays consisting of wide aperture lasers diodes. Selection of the "in-phase" supermode, preferable for most of the cases, is attained in the external quarter Talbot (Lc=ZT/4=d 2 /2l) cavity due to the output mirror tilt at the angle jm=l/2d. Analysis of the parameters that influence on the phase-locking is given. Our experiments confirm theoretical predictions of the system stability and adequate selectivity for the laser diode array fill factor (FF) FF=0.6.
ABSTRACT
To intensify a heat transfer in high-power emitters based on laser diode bars we propose the use of a heat sink from a porous permeable material cooled by a fluid flow [1-3]. The main advantage of this class of materials is the possibility of removing significant heat flows with compact heat sink. An analysis of the characteristic values of the thermal loads and their relations with the material and liquid parameters drawn from an one-dimensional model of stationary one-sided heat exchange shows the possibility of heat flow removal of more than 1.5 kW/cm 2 at room temperature in a liquid. Methods for improving the effectiveness of the strategy are considered.
ABSTRACT
Amplification in free-electron lasers exploiting media with periodically modulated refractive indices is studied in the regime of a large modulation. The conditions for realization of the large-modulation regime in a superlattice-like medium are established. The maximized gain, the corresponding saturation field and efficiency, as well as the optimal electron energy and propagation direction are determined. It is shown that the large-modulation regime makes it possible to extend significantly the operation frequency domain of the FEL employing a low-relativistic electron beam. Relationship with the Cherenkov and stimulated resonance-transition-radiation FELs is discussed. This research is partially supported by RFBR grant 97-02-17783.
