High-power CW oscillation of 1.3-µm wavelength InP-based photonic-crystal surface-emitting lasers
Yuhki Itoh, Naoya Kono, Daisuke Inoue, Naoki Fujiwara, Makoto Ogasawara, Kosuke Fujii, Hiroyuki Yoshinaga, Hideki Yagi, Masaki Yanagisawa, Masahiro Yoshida, Takuya Inoue, Menaka De Zoysa, Kenji Ishizaki, Susumu Noda
Abstract
We demonstrate high-power continuous-wave (CW) lasing oscillation of 1.3-µm wavelength InP-based photonic-crystal surface-emitting lasers (PCSELs). Single-mode operation with an output power of over 100 mW, a side-mode suppression ratio (SMSR) of over 50 dB, and a narrow single-lobe beam with a divergence angle of below 1.2° are successfully achieved by using a double-lattice photonic crystal structure consisting of high-aspect-ratio deep air holes. The double lattice is designed to enhance both the in-plane optical feedback and the surface radiation effects in the photonic crystal. The coupling coefficients for 180 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:msup> <mml:mi/> <mml:mo>∘</mml:mo> </mml:msup> </mml:math> , +90 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:msup> <mml:mi/> <mml:mo>∘</mml:mo> </mml:msup> </mml:math> , and -90 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:msup> <mml:mi/> <mml:mo>∘</mml:mo> </mml:msup> </mml:math> diffractions are estimated from the measurements of the photonic band structure as κ 1 D = 417 cm −1 , κ 2 D + = 135 cm −1 , and κ 2 D − = 65 cm −1 , respectively. The stable single-mode, high-beam-quality operation is attributed to these large coupling coefficients introduced by the asymmetric double-lattice structure.