Tunable colloidal quantum dot distributed feedback lasers integrated on a continuously chirped surface grating

Abstract

Continuously tunable colloidal quantum dot distributed feedback lasers are fabricated on a chirped surface grating generated by a laser interference lithography apparatus equipped with a cylindrical Lloyd's mirror.

Tuning Laser Threshold within the Large Optical Gain Bandwidth of Halide Perovskite Thin Films

“…For other chirped gratings fabricated by laser interference lithography using a curved Lloyd mirror system, the tuning rate is limited by the curvature of the Lloyd mirror (a few nm/mm) so that the tuning range becomes much narrower than the maximum achievable optical gain bandwidth. 35 However, for the ones here, fabricated via electron beam lithography (EBL), easy, precise, and fine control of the lasing wavelength is possible by simply changing the grating dimension. Although EBL is a slow process compared to laser interference lithography, the chirped gratings fabricated by EBL can further be replicated using nanoimprint lithography for high-throughput mass production.…”

“…As perovskite materials have already proven to be a promising coherent light source, realization of continuous and widely tunable lasing emission from perovskite thin films is useful for solid-state lighting, display, optical communication, integrated circuits, and sensing applications. 35,40,41 In this work, we demonstrate continuously tunable singlemode lasing over a wide spectral range from a single perovskite laser device by incorporating period-varying chirped Bragg grating structures. For CH 3 NH 3 PbI 3 (MAPbI 3 ) perovskite thin films, the tuning range can be as wide as 46 nm (∼90 meV) with a spectral tuning spacing, Δλ lasing of 1. threshold of less than 10 μJ/cm 2 , across the entire tuning range.…”

“…Lasing near the deep-blue (∼425 nm) at room temperature has also been unlocked recently from nanowires, microcubes, and low dimensional wide-bandgap CsPbCl 3 perovskites thin film. − However, continuously tunable lasing or multiwavelength lasing from a single perovskite thin film device has not been demonstrated. To date, organic semiconductors and colloidal quantum dots have employed various approaches to provide continuous tunability, such as wedge-shaped layer structures, , chirped cavities, − flexible substrates, − and temperature control . However, these approaches have often failed to fully utilize the gain bandwidth of the amplifying medium, limiting the precise and fine control of the lasing emission and tuning over a range much narrower (∼10 nm or 50 meV) than their optical gain bandwidth due to mechanical instability or another limitation of the cavity geometry.…”

“…However, these approaches have often failed to fully utilize the gain bandwidth of the amplifying medium, limiting the precise and fine control of the lasing emission and tuning over a range much narrower (∼10 nm or 50 meV) than their optical gain bandwidth due to mechanical instability or another limitation of the cavity geometry. As perovskite materials have already proven to be a promising coherent light source, realization of continuous and widely tunable lasing emission from perovskite thin films is useful for solid-state lighting, display, optical communication, integrated circuits, and sensing applications. ,, …”

Piezo-Actuated One-Axis Vibrational Patterning for Mold-Free Continuous Fabrication of High-Precision Period-Programmable Micro- and Nanopatterns

“…Some exemplary results are provided in Figure S5 in the Supporting Information. These period-variable chirped surface gratings are useful for many photonic applications including linear Fresnel light collectors, − optical sensors, , and lasing devices, , and the real-time f -modulated POP may present another practical route for their fabrication. Notably, the period-tunable MN patterning can be conducted also by modulating v with the constant f indentation in POP, as similarly demonstrated in VIP …”