in this work, laser bending of perforated sheets has been investigated numerically. laser bending of perforated sheets is more complicated than non-perforated sheets due to their complex geometries. in this paper, laser bending of perforated sheets is studied numerically in the form of thermo-mechanical analysis with abaqus/implicit code. for this purpose, the effects of process and sheet param...

background: laser-tissue interaction on low-level laser therapy (lllt) has widespread medical applications (e.g., improved wound healing). the tensile strength of radiated tissue by lllt is known to be increased mainly because of cross collagen bands developed after radiation. objective: in this work, we studied the instantaneous effect of radiation of polarized laser beam on the viscoelastic t...

The modulation response, relative intensity noise (RIN) and frequency noise (FN) characteristics of quantum dot (QD) lasers are investigated theoretically in the presence of an external optical beam. Using small signal analysis of the rate equations for carriers and photons, it is demonstrated that by injecting excess carriers into the QDs excited state through optical pumping, the modulation r...

In this paper, we present a high accuracy laser range finder and velocimeter using ultra-fast time-to-digital converter (TDC). The system operation is based on the measuring the round-trip time of a narrow laser pulse. A low-dark current high-speed PIN photodiode is used to detect the triggered laser beam and to produce start signal. The pulsed laser diode generates 45W optical power at 30ns du...

Copropagation of a laser pulse and a relativistic electron beam in a corrugated plasma channel has been proposed for the direct laser acceleration of electrons [Palastro, Phys. Rev. E 77, 036405 (2008)]. The corrugated plasma channel allows for the guiding of laser pulses composed of subluminal spatial harmonics. Phase matching between the electron beam and the spatial harmonics results in acce...

Under degenerate resonator configuration and tightly focused pump beam in a linear-cavity solid-state laser, the spatial hole-burning effect can be suppressed. This laser can attain very high intensity in the gain medium due to shrinkage of its beam waist to match the pump beam and therefore most of its gain is depleted even by a standing wave. This was demonstrated by a simulation with spatial...

Laser-based missile-defence systems are being increasingly employed on aircraft to provide protection when attacked by optically-guided weapons. In some engagements the laser beam must pass through the exhaust gases of the aircraft. To predict the increase in laser beam divergence and jitter of the laser beam direction, an understanding of the exhaust gas structure and its influence is required...

Micro-channels are made over the Ag+/Na+ ion-exchanged soda-lime glass surface by interaction of an intense Ar+ laser beam and the silver ions inside the glass matrix. The Ar+ laser beam reduces the Ag+ ions inside the matrix. The Ag+ atoms aggregate into silver nano-clusters around the interaction area, inside the glass matrix. Aggregation of the silver atoms and the thermal effects of the int...