Future Direction of High Power Diode Laser Technologies for Wide Applications and High Market Growth

High power diode lasers (HPDLs) offer the highest wall-plug efficiency, highest specific power (Power-to-weight ratio) and arguably the lowest cost and highest reliability among all lasers, especially compared to fiber lasers and diode pumped solid state lasers (DPSSLs). However, in today’ real applications, the market is still dominated by fiber lasers and DPSSLs although direct diode laser applications are growing. The more widespread applications and thus higher market growth of HPDLs are limited by the poor beam quality of HPDLs. Naturally, one of directions of HPDL technologies is to improve the beam quality from semiconductor design and fabrication point of view. On the other hand, for most of the applications no matter it is laser matter interaction or information transmitting or illumination, three factors determine if a laser can be used for a specific application: power density, beam shape, intensity profile. It is known that beam shaping is the process of redistributing the irradiance and phase of a beam of optical radiation. Although the etendue of a light source can only remain constant or increase as light propagates through an optical system, the beam parameter product (BPP) of a light source can be reduced in one direction with the sacrifice of the other direction by beam shaping. Beam shaping micro-optics have the possibility to control and deliver photons emitted by light sources to the right place at the right time. To unlock the potential of HPDLs and make light energy emitted from HPDLs usable to open up new dimensions in applications and achieve high market growth, diode laser light sources and beam shaping micro-optics should be designed cohesively. Successful examples of matching of diode laser light sources and beam shaping micro-optics driving new applications are presented.