Broadband nonlinear optical properties of red fluorescent carbon dots

Recent advances in red-emissive carbon dots and their biomedical applications

“…9a–d). 74 Furthermore, the nonlinear absorption changes from saturated absorption to two-photon absorption in the NIR region. Li et al used a 1400 nm femtosecond laser to excite CDs in dimethyl sulfoxide, which produces both two-photon induced NIR emission and three-photon induced red emission from CDs (Fig.…”

Photoinduced absorption and linear/nonlinear emission of assembled carbon dot–silica nanocomposites for cellular imaging

“…HeLa cells were cultured referring to our previous work. 17 Specifically, representative HeLa cancer cells were designated as the research subject. The as-prepared medium was used to culture HeLa cells, and the medium was obtained by adding both 10% of fetal bovine serum (FBS) and 1% of penicillin-streptomycin (PS) to the DMEM (Dulbecco's modified Eagle's medium) solution.…”

“…In a bio-spectral window, the 1PEF usually shows obvious shortcomings in the bio-imaging field, whereas multi-photon excited fluorescence or phosphorescence imaging can overcome those defects to show higher resolution, weaker photo-cytotoxicity, stronger resistance to the interference from the background/ excitation light, and deeper penetration depth compared with 1PEF imaging. 12,[14][15][16] The nonlinear optical properties of CDs mainly focused on the two-photon absorption (2PA) process, [17][18][19][20] 2PA/3PA process, 19,20 4PA process, 19 etc. We have previously investigated the conversion from saturable absorption (SA) to anti-saturation absorption, which is a typical 2PA process of CDs observed by ultrafast nonlinear optical spectroscopy.…”

Stochastic Nature and Intramolecular Coupling in Optical Response Profiles: Critical Analysis through Semiclassical Models

“…Garcia-Golding presented a theoretical model and with the support of experimental data estimated the product of MCG and DQCI relaxation times and studied the saturation effects of the pumping beam on the population decay of this dye in different solvents . With the purpose of limiting the present work of revision referring to the NLO, our considerations will be referred to classic descriptions of the electromagnetic field and varied situations of the chemical system of study with emphasis in detailing the molecular structure and how this one, can have influences of correlation in the description of the NLO. − Al-Saidi and Abdulkareen pointed out important modifications in the optical properties in chemical solutions as a function of the concentration of the organic dye being analyzed, the variation being a direct effect from a nonlinear saturable absorption, as an important issue in the analysis of optical limiters. The effect of propagation in pulsed FWM, of spontaneous or counter propagating nature, and the theory derived from the propagation effects in this nonlinear time-resolved process, puts into perspective the relevance of knowing the behavior of the beams in their optical path, where the absorptive and dispersive processes play an important role in understanding the propagation, as well as in deciphering some properties associated with symmetry, inherent to the incident and emerging fields in the FWM scheme …”