Temporal dynamics of two-photon-pumped amplified spontaneous emission in slab organic crystals

Abstract

We have studied the ultrafast dynamics of two-photon-pumped amplified spontaneous emission (ASE) from a single crystal by the time-resolved fluorescence upconversion technique. With the increase of two-photon pump intensities, the emission decay time is dramatically shortened by 30 times (from 3ns to approximately 87 ps), and the energy migration rate is acutely enhanced when ASE occurs. The stripe length is also found to play an important role in the formation of the ASE. Meanwhile, the gain coefficient is evaluated to be 15cm(-1) for 560nm at an excitation intensity of 2.3mJ/pulse/cm(2) by the variable stripe length technique.

Ultrafast Dynamics of Polariton Cooling and Renormalization in an Organic Single-Crystal Microcavity under Nonresonant Pumping

“…At early times, <∼1 ps, the LPB 3 mode clearly shows an ultrafast emission component (see Figure c). This ultrafast emission component is not amplified spontaneous emission (ASE) because, as shown in Section 8 in the Supporting Information, the ASE component of a bare BP1T-CN crystal has a ∼50 ps time constant ,, and is 2 orders of magnitude longer than the result for the microcavity sample. We compared the observed emission dynamics with a modeled dynamics for polariton population in the LPB minimum.…”

Distributed Feedback Lasers Based on Thiophene/Phenylene Co‐Oligomer Single Crystals

“…The long‐range order and high chemical purity in crystals make them intrinsically excellent in charge‐carrier transport properties, whose mobility could be significantly increased by three orders or more from their amorphous phase to the single‐crystal phase without any serious luminescence efficiency decrease 12–15. Notable achievements on the amplified spontaneous emission (ASE) have been attained in a large number of crystalline materials 16–22. For a laser device, resonator structure is necessary to apply the positive optical feedback, which may reduce the lasing threshold significantly.…”

High-Quality Large-Size Organic Crystals Prepared by Improved Physical Vapor Growth Technique and Their Optical Gain Properties

“…Over past few years, organic single crystalline materials have attracted a great deal of research interest in the optoelectronic or photonic field because of their high stimulated cross sections, large and ultrafast nonlinear responses, and broad spectral tunability. Various devices, such as organic field-effect transistors (OFETs), − light-emitting transistors (LETs), , optically pumped organic semiconductor lasers (OSLs), − and upconversion lasers − based on the organic crystals have been demonstrated. Their long-range order not only reveals the performance limits of organic semiconductor materials but also provides unique insight into their intrinsic optoelectronic properties .…”