Compact and efficient green lasers for mobile projector applications

Abstract

Efficient and very‐compact projectors embedded into mobile consumer‐electronic devices, such as handsets, media players, gaming consoles, and GPS units, will enable new consumer use and industry business models. A keystone component for such projectors is a green laser that is commensurately efficient and compact. A synthetic green‐laser architecture that can achieve efficiencies of 15% is described. The architecture consists of an infrared distributed Bragg reflector laser coupled into a second‐harmonic‐generation device for conversion to green.

36‐1: Invited Paper: The Revolution in Solid State Light Sources in Projection

“…The simplest non-linear conversion process is frequency doubling, where 1064nm IR light is frequency doubled to produce 532nm green light, as in Figure 4 [22] and Figure 5. [23]…”

“…Green laser from Corning using external frequency doubling (Second Harmonic Generation)[22] Green laser from Novalux using intra-cavity frequency doubling. (Redrawn from[23])More complex non-linear wavelength conversion systems have also been used in projection systems and are currently in use in cinema projectors not only for the green but also sometimes for the red and blue.…”

Tapered laser diode with linearly effective-refractive-index variation waveguide

“…The good quality beam LD of 808 nm is meaningful because the 808 nm LD is well known as end pumping sources of DPM crystal consisting of Nd:YVO 4 and KTP crystal without lens to make green laser and the stable formation of thermal lens in the Nd:YVO 4 is important and therefore single mode-like beam is needed [4]. In addition, the wall plug efficiency (WPE) of DPSS green laser (WPE ~ 20 %) is still higher than other lasers such as 1064 nm pumped PPLN based green laser (WPE ~ 15 %) and direct InGaN based green LDs (WPE ~ 8%) [5][6][7]. We fabricated the tapered LDs with 808 nm GaAsP/InGaP/AlGaInP LD structure with single quantum well (QW) using standard LD processing and investigated the characteristics of the tapered LDs with aperture size of 30, 50, 70 um.…”