Room temperature surface emission on large-area photonic crystal quantum cascade lasers

• Published in: Applied physics letters Vol. 114; no. 3
• Main Authors: Liang, Y., Wang, Z., Wolf, J., Gini, E., Beck, M., Meng, B., Faist, J., Scalari, G.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 21-01-2019
• Subjects: Applied physics; Divergence; Emission; Far fields; Photonic crystals; Quantum cascade lasers; Quantum theory; Room temperature
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.5082279

We design and fabricate large-area (1.1 mm × 1.1 mm) photonic crystal quantum cascade lasers, enabling single-mode (wavelength ∼ 8.5 µm) surface emission at room temperature, with a maximum peak power up to 176 mW. The beam divergence is <1∘ and with no side-lobes. Moreover, by introducing asymmetry into the photonic crystal pillar shape, a single-lobed far-field pattern is realized. The photonic band structure is measured with high spectral (0.72 cm−1) and angular (0.1°) resolution by using the photonic crystal quantum cascade laser itself as a detector.