Manufacturing of semiconductor devices consists of many equally significant stages. Every improperly-performed detail
may cause abnormal functioning of the device which is very undesirable. Electrical contact manufacturing guarantees the
connection between the "inner world" containing phenomena on the molecular level of the device and the "outer world"
including connections to other objects and enabling consumer usability. In the following thesis two kinds of pastes
containing silver nanoparticles in polymer matrix have been used to make electrical contacts. Performed layers have been
compared with sputtering-method made contacts.
The quality of the beam emitted by high-power laser diodes is still the main disadvantage of these devices. One of the
ways to improve it is to design diode as a matrix of narrow active stripes – so called: phase-locked arrays. The optical
coupling which is occurs in such devices causes the emission in the form of a few almost diffraction limited beams
(lobes). Unfortunately, because of temperature dependence of refractive indices this coupling often disappears at high
drive currents. In this paper the CW operation (up to 4Ith) of the phase-locked semiconductor laser arrays is reported. The
devices are based on asymmetric heterostructure which is designed for improving thermal and electrical resistances. The
single supermode operation is obtained and the lasers are emitted up to 1 W of the optical power in CW.
The laser diodes (LD) have numerous applications and promise to become key elements for next generation laser
technologies. LD are usually operated under conditions of heavy thermal load. As a result, the devices are affected by
aging processes leading to changes of the operation parameters, degradation and, eventually, complete failure.
Degradation of high power semiconductor lasers remains a serious problem for practical application of these devices. We
investigated the effect of mounting induced strain and defects on the performance of high power laser. In this paper
measurements of the temperature distribution and the electroluminescence along the cavity of InGaAs quantum well
lasers before and after accelerated aging processes are presented. The electro-optical parameters of the high output power
laser diodes, such as emission wavelength, output power, threshold current, slope efficiency, and operating lifetime are
presented too.
Low quality of the optical beam emitted by high-power laser diodes is the main disadvantage of these devices. The two
most important reasons are highly non-Gaussian beam profile with relatively wide divergence in the junction plane and
the filamentation effect. Designing laser diode as an array of narrow, close to each other single-mode waveguides is one
of the solutions to this problem. In such devices called phase locked arrays (PLA) there is no room for filaments
formation. The consequence of optical coupling of many single-mode waveguides is the device emission in the form of
few almost diffraction limited beams. Because of losses in regions between active stripes the PLA devices have,
however, somewhat higher threshold current and lower slope efficiencies compared to wide-stripe devices of similar
geometry. In this work the concept of the high-power laser diode resonator consisted of joined PLA and wide stripe
segments is proposed. Resulting changes of electro-optical characteristics of PLA are discussed. The devices are based
on the asymmetric heterostructure designed for improvement of the catastrophic optical damage threshold as well as
thermal and electrical resistances. Due to reduced distance from the active layer to surface in this heterostructure, better
stability of current (and gain) distribution with changing drive level is expected. This could lead to better stability of
optical field distribution and supermodes control. The beam divergence reduction in the direction perpendicular of the
junction plane has been also achieved.
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