Angled cavity photonic crystal lasers with asymmetrical high-order surface gratings

Abstract

980 nm angled cavity photonic crystal (PC) laser diodes with asymmetrical high-order surface gratings (aHSGs) are proposed and fabricated. The one-dimensional PC structure in the epitaxy is used to expand the fundamental transverse mode and reduce the vertical divergence. An angled cavity with aHSGs is fabricated to achieve a nearly diffraction-limited beam quality and narrow spectral width. Experimentally, a continuous-wave output of 0.85 W/facet, a low divergence of 1.5 × 10.6°, and a narrow spectral width of 0.07 nm are achieved. The lateral beam quality is superior with an of 1.96.

Semiconductor photonic crystal laser

“…[67]. The obtained CW output power reached 1.26 W. Zheng et al [72] also designed a 980 nm angled cavity longitudinal PBC laser diode with asymmetrical high-order surface gratings (aHSGs) (see Fig. 8(b)).…”

“…The device had a vertical M2 value of 1.97 and a lateral M2 value of 1.34 at a current of 0.7 A, indicating a nearly diffraction-limited beam quality. [69] and (b) aHSGs [72] longitudinal PBC lasers. The SEM image (inset in (a)) shows the waveguide at the facet.…”

“…Fig.8. (color online) Schematic structures of (a) the 2D tilt[69] and (b) aHSGs[72] longitudinal PBC lasers. The SEM image (inset in (a)) shows the waveguide at the facet.…”

Broad-area laser diodes with on-chip combined angled cavity

“…These approaches show their advantages, but also with some limitations. The angled cavity [16][17][18][19][20][21] was a promising idea, and the corresponding broad-area lasers had demonstrated the high-brightness and single-lobe far field (FF), which was attributed to the mode control of the tilted waveguide and supplied a simple and robust solution for power scaling with good beam quality. The other approach to improve the brightness of diode lasers was the on-chip combining based on the Y-junction tree array [22] or V-junction resonators [23,24] .…”

“…The homologous result was also found in angled cavity lasers [19] . One reason for the increased threshold current density is the large mode loss of the transverse mode in the zigzag oscillation [20,21] , while the high reflection (HR) of deep etched sidewalls can improve this situation. The other possible reason behind this might be the suppressed resonance in the angled cavity [18] .…”