Soft‐Lithographed Up‐Converted Distributed Feedback Visible Lasers Based on CdSe–CdZnS–ZnS Quantum Dots

TLDR

The authors present a solution‑deposited up‑converted distributed feedback laser prototype. They fabricate the laser by soft‑lithographing a sol‑gel silica/germania microcavity and depositing a quantum‑dot ink of CdSe–CdZnS–ZnS/zirconia onto a DFB grating, creating an all‑solution‑processed microcavity laser. The quantum dots exhibit high one‑ and two‑photon absorption cross‑sections (1×10⁻¹⁴ cm² and 5×10⁴ GM) and a 220 ps Auger recombination lifetime, enabling them to serve as optically pumped gain media in both regimes.

Abstract

Abstract The development of a solution‐deposited up‐converted distributed feedback laser prototype is presented. It employs a sol–gel silica/germania soft‐lithographed microcavity and CdSe–CdZnS–ZnS quantum dot/sol–gel zirconia composites as optical gain material. Characterization of the linear and nonlinear optical properties of quantum dots establishes their high absorption cross‐sections in the one‐ and two‐ photon absorption regimes to be 1 × 10 −14 cm 2 and 5 × 10 4 GM, respectively. In addition, ultrafast transient absorption dynamics measurements of the graded seal quantum dots reveal that the Auger recombination lifetime is 220 ps, a value two times higher than that of the corresponding CdSe core. These factors enable the use of such quantum dots as optically pumped gain media, operating in the one‐ and two‐photon absorption regime. The incorporation of CdSe–CdZnS–ZnS quantum dots within a zirconia host matrix affords a quantum‐dot ink that can be directly deposited on our soft‐lithographed distributed feedback grating to form an all‐solution‐processed microcavity laser.