Phase-locked laser array

A phase-locked laser array comprises a body of semiconductor material having means for defining a plurality of substantially parallel lasing zones which are spaced an effective distance apart so that the modes of the adjacent lasing zones are phase-locked to one another. One of the array electrodes comprises a plurality of electrical contacts to the body between the lasing zones. These contacts provide an enhanced current density profile and thus an increase in the gain in the regions between the lasing zones so that zero degree phase-shift operation between adjacent lasing zones is achievable

Semiconductor laser having a non-absorbing passive region with beam guiding

A laser comprises a semiconductor body having a pair of end faces and including an active region comprising adjacent active and guide layers which is spaced a distance from the end face and a passive region comprising adjacent non-absorbing guide and mode control layers which extends between the active region and the end face. The combination of the guide and mode control layers provides a weak positive index waveguide in the lateral direction thereby providing lateral mode control in the passive region between the active region and the end face

Phase-locked laser array

A phase-locked laser array comprises a substrate with two spaced-apart pluralities of channels extending towards different reflecting surfaces of the array. The axes of symmetry of the channels of one plurality are offset from the axes of symmetry of the channels of the second plurality. Coupling of light propagating in the optical waveguides over one plurality of channels into the waveguides over the second plurality of channels induces a zero phase difference between the laser oscillations of adjacent channels

Mode-Locking of High-Power Resonant-Optical-Waveguide Diode Laser Arrays

We report the first mode-locked operation of a resonant optical waveguide (ROW semiconductor laser array. Pulsewidths as short as 23 ps and peak powers of over 1W are generated in a single-lobed beam

Management of the hip periprosthetic fractures

Orthopedics and Traumatology Clinic ”Vitalie Bețișor”, State University of Medicine and Pharmacy ”Nicolae Testemițanu”, Republic of Moldova, UMP “Grigore T. Popa”, Iași, Romania, Al VIII-lea Congres Naţional de Ortopedie și Traumatologie cu participare internaţională 12-14 octombrie 2016The purpose of the study: The analysis of the treatment methods in periprosthetic fractures after hip arthroplasty, with correlation between the experience of the authors and literature data. Methods: During the years 2010-2014 in our clinic were performed 67 revision surgical procedures of periprosthetic fractures after the hip replacements. Of these 25 were males and 42 were females; the mean cohort age was 64 year, ranging from 54 ap to 79 years. Elapsed time from the primary arthroplasty up to the revision of the periprosthetic fractures varied from 2 months up to the 13 years. Cases were staggered according to Vancouver classification. We have encountered fractures of type AG in 4 cases, type AL - 3 cases, type B1 – 12 cases, type B2 – 14 cases, type B3 – 7 cases, type C – 27 cases. Fractures of the type A have been treated with simple wire fixation (4 cases) tension band wiring (3 cases). Fractures of the type B1 were treated by the plate osteosynthesis; type B2 and B3 – by revision arthroplasty. In fractures type C we performed the osteosyntesis by the plates with angular stability in 15 cases or regular plates with association of the bone grafts in 12 cases. Results: In fractures of the type A we found one case of osteosyntesis instability, which was well tolerated by the patient. Fractures of the type B represent one of the biggest problems. Especially type B1 and B2, when was difficult to differentiate if the stem was stable or not. In 3 cases we did mistakes in appreciation of the type B1 and performed the osteosyntesis. In all these cases occured the instability of the stem, that led to the revision arthroplasty procedure. In cases of the fractures type C we met the problem of the associated osteoporosis. This led to technical difficulties in achieving stable osteosynthesis by regular plates. Conclusions: The results confirm that correct classification, compliance with treatment protocols of the hip periprosthetic fractures and strict differencition between different types of the fractures can lead to good functional result

Temporal behavior of resonant‐optical‐waveguide phase‐locked diode laser arrays

Measurements of the temporal and spatial behavior of resonant optical waveguide (ROW) laser arrays with significant interelement loss reveal the presence of sustained self‐pulsations in the output intensity of the laser. The mechanism responsible for pulsations is believed to be saturable absorption arising from the presence of absorbers in the interelement regions. This is experimentally confirmed in that reduction or elimination of the interelement loss suppresses the pulsations. Quiescent behavior is obtained to at least 0.45 W continuous wave power and 3.4 times threshold in near‐diffraction‐limited beams from devices with negligible interelement loss.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70212/2/APPLAB-64-7-827-1.pd

Design for high-power single-mode operation from 2-D surface-emitting ROW-DFB lasers

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Phase-locked laser arrays revisited

This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder