High-brightness (meaning high power in a narrow well directed beam) semiconductor lasers are in high demand for laser printers, laser surgery, and various other applications in industry and medicine. However, to achieve high power, it is important to minimise internal losses in the laser, whereas to achieve a well directed beam, a broad near field of the laser (laser mode profile) is required. The two requirements are conflicting because the broad mode penetrates not just the core of the waveguide but the very lossy contact layers. everal successful designs have been proposed to reconcile these two constraints, but all fail at the very high power regime. We have proposed and analysed theoretically and numerically a new design, called asymmetric non-broadened waveguide laser, which maintains narrow beam and low losses even at ultrahigh power (tens of Watt from a single laser) operation. We have shown that these devices promise superior behaviour to existing constructions in terms of power, beam quality, and temperature sensitivity.
As a secondary output of our work, we have also furthered the understanding of the semiconductor laser operation and proposed analytical models of the very-high-power operation regime which so far have only been described using complex numerical models. The theory describes the available experiments on existing laser constructions well.
The fabrication of the laser construction proposed by us is expected in the near future, which will doubtless lead to more theoretical work in its turn.
In the recent development, in a joint project with the University of Oulu in Finland, a modification of this structure has also been proposed for high-power short-pulse sources for use in laser radars.
This work was done in collaboration with Boris Ryvkin of the A F Ioffe Physico-Technical Institute, St Petersburg, Russia.
- E A Avrutin
- Start: October 2005