• Demonstration of an enhancement in the modulation bandwidth from 16 GHz to 28 GHz in an injection locked semiconductor laser with a coincident reduction in parasitic chirp. • Demonstration of room-temperature, continuous-wave operation of the first bipolar cascade laser. This laser demonstrated an internal efficiency of 150% and a measured external modulation efficiency of 99.3%. Continuous-w...

We report preliminary results on the feasibility of a compact source of high power and high intensity coherent radiation emitted from an array of semiconductor diode lasers via the injection of a controlled electromagnetic field into the cavity of each laser. The new source is expected to generate coherent radiation of the order of magnitude of 10 Watts and to spawn a new laser technology of co...

Time-dependent coupled mode theory is used to investigate the stability of phase-locked semiconductor laser arrays. The output of individual array elements is dynamically unstable and exhibits large amplitude chaotic pulsations. The total output initially exhibits damped relaxation oscillations and then settles down. to a quasi-steady state characterized by small amplitude fluctuations. The the...

Phased array 1-to-N-way resonators can be relevant in the realization of high output powers from semiconductor laser arrays and have significant advantages over Talbot resonators. However, depending on the number of array elements, the intracavity power density on the output facet can be high, resulting in catastrophic optical mirror damage. We present a variant of the original design that over...

results the simulation results showed that the penetration depth and temperature rise of 980 nm wavelengths were different from those of 1064 nm wavelength. it appeared that 1064 nm wavelength penetrated to deeper layers of tissue compared with 980 nm. moreover, temperature rise during 1064 nm irradiation led to temperature increase in allowable ranges. the findings proved the reason why 1064 n...

A time-dependent, two-dimensional model of a semiconductor laser array is numerically studied by means of Θand Newton-Raphson methods. A parallel version of the BiCGSTAB algorithm for the solution of the linear equations resulting from the Newton-Raphson technique is presented. It is shown that the proposed method reduces by half the number of messages and, by means of communications overlappin...

We have demonstrated that a hybrid laser array, combining graded-photonic-heterostructure terahertz semiconductor lasers with a ring resonator, allows the relative phase (either symmetric or anti-symmetric) between the sources to be fixed by design. We have successfully phase-locked up to five separate lasers. Compared with a single device, we achieved a clear narrowing of the output beam profile.

We study the dynamics of an array of single mode semiconductor lasers globally but weakly coupled by a common external feedback mirror and by nearest neighbor interactions. We seek to determine the conditions under which all lasers of the array are in phase, whether in a steady, periodic, quasiperiodic, or chaotic regime, in order to maximize the output far field intensity. We show that the del...

The passive sections of a monolithic device must have a wider bandgap than the active regions to reduce losses due to direct interband absorption. Such bandgap engineering is usually realized by complicated regrown butt-joint or selective-area growth techniques. We, however, have developed a simple, flexible and low-cost alternative technique – quantum well intermixing (QWI) – to increase the b...