Passive optical switches based on endohedral fullerenes

Abstract

Reverse saturable absorption in fullerenes has been widely used to realize excellent passive optical limiters for the visible region up to 650 nm. However, there is still a need for passive optical switches and limiters with a low limiting threshold (<0.5 J/cm 2) and higher damage limits. The electronic structure of fullerenes can be modified either through doping or by the encapsulation of endohedral clusters to achieve exotic quantum states of matter such as superconductivity. Building on this ability, we show that the encapsulation of Sc 3 N, Lu 3 N or Y 3 N in C 80 alters the HOMO-LUMO gap and leads to passive optical switches with a significantly low limiting threshold (0.3 J/cm 2) and a wider operation window (average pulse energy>0.3 mJ in the ns regime).

Saturable Absorption in 2D Ti3C2 MXene Thin Films for Passive Photonic Diodes

“…With the sample experiencing different optical intensities at each z position, the corresponding transmittance was recorded by a calibrated photodetector (RjP‐7620, Laserprobe, Inc) placed on the sample translation axis. A more detailed description of our Z‐scan technique can be found elsewhere . As described in the article, the space‐time slicing model was performed by iteratively solving light propagation equations in MATLAB using Runge–Kutta method.…”

“…The overall response is an increase in light transmission (higher than linear transmittance) if the SA effects overwhelm RSA. On the other hand, in the reverse direction (C 60 followed by Ti 3 C 2 T x MXene), the input laser pulse with same fluence as in the forward direction ( F in > I s ) is attenuated below I s by C 60 due to multiphoton absorption . The transmitted laser pulse ( F transmitted < I S ) from C 60 does not elicit a high transmittance through the Ti 3 C 2 T x film leading to a decreased transmission (Figure S4, Supporting Information).…”

Unveiling the role of upper excited electronic states in the photochemistry and laser performance of anti-B18H22

“…Interestingly, this excess of ESA reveals that anti-B18H22 is a "reverse saturable absorber" that could be exploited in optical limiting applications. 16 Unfortunately, however, this same excess has dramatic consequences for the laser performance, as will transpire later on. The value of the ESA cross section at the pump wavelength has been included in Figure 1a (red dot) for comparison purposes.…”

Ultraviolet Photodetectors Based on Dimetallofullerene Lu2@Cs(6)-C82 Nanorods

“…Photodetectors, which can translate incident radiation into electrical signals, have attracted continuous attention in imaging techniques, ambient sensing, light-emitting diodes, wearable electronic devices, etc. − Organic single crystals can facilitate charge transport and exciton diffusion as well as possess excellent performance compared to their bulk counterparts due to the lack of structural defects and grain boundaries. − Among the most widely studied organic molecules, fullerenes are ideal building blocks to controllably construct well-defined single-crystalline structures which have attracted particular attention in photodetectors. − For example, Shrestha et al reported that the photogenerated charge carriers in single-crystalline C 60 nanorods are improved compared with those in pristine C 60 . Fang et al fabricated high-quality micrometer-sized C 60 nanofibers in supramolecular gels, which exhibit high responsivity, further implying the potential optoelectronic applications of fullerene materials.…”