Abstract
The light emission characteristics of GaInAsP semiconductors in aqueous solutions are modified by the surface charge, depending on the balance between radiative and nonradiative recombination. This Letter demonstrates the application of a GaInAsP photonic crystal band-edge laser in sensing a solution pH, which reflects the surface charge. The sensitivity is enhanced by a hybrid of fractal honeycomb and close-packed structures with a large surface-to-volume ratio and a high quality factor ($Q$), which allows a low threshold carrier density. We experimentally obtained a maximum pH sensitivity of 1.9 dB/pH near the threshold and a signal-to-noise ratio of 52/pH (pH resolution of 0.019) at a pump power 2.4 times the threshold where the intensity noise diminished.
© 2020 Optical Society of America
Full Article | PDF ArticleMore Like This
Keisuke Watanabe and Toshihiko Baba
Opt. Express 27(18) 24978-24988 (2019)
Yun Meng, Kai Zou, Nan Hu, Xiaojian Lan, Liang Xu, Julien Zichi, Stephan Steinhauer, Val Zwiller, and Xiaolong Hu
Opt. Lett. 45(2) 471-474 (2020)
Jonas Leuermann, Vladimir Stamenkovic, Patricia Ramirez-Priego, Alejandro Sánchez-Postigo, Adrián Fernández-Gavela, Cole A. Chapman, Ryan C. Bailey, Laura M. Lechuga, Ezequiel Perez-Inestrosa, Daniel Collado, Robert Halir, and Íñigo Molina-Fernández
Opt. Lett. 45(24) 6595-6598 (2020)