| 1. |
- Kindahl, Tomas, et al.
(författare)
-
Photophysical and DFT Characterization of Novel Pt(II)-Coupled 2,5-Diaryloxazoles for Nonlinear Optical Absorption
- 2012
-
Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 116:47, s. 11519-11530
-
Tidskriftsartikel (refereegranskat)abstract
- Several new bis-phosphine platinum(II) complexes with 2,5-diaryl-substituted oxazole-containing alkyne ligands have been synthesized and optically characterized in solution. Measurements of nonlinear absorption showed strong attenuation of laser light at 532 and 600 nm. The light absorption of the Pt complexes was shifted from the near-UV region for the ground state to the red region for the excited triplet state, and was associated with large extinction coefficients. The optical limiting effect can be explained by triplet-triplet excited state absorption in conjunction with fast excited singlet to-triplet intersystem crossing and slow triplet to-ground-state decay, in comparison with the pulse length of the laser. DFT calculations show good predictability of the S-0-S-1 and S-0-T-1 energy gaps and offer insight into the interaction strength between Pt and the alkyne ligands. The use of this type of ligand, with weak absorption for the Pt(II) complexes in the visual wavelength range as a key feature, enables the possibility to further improve these molecular systems for nonlinear absorption applications.
|
|
| 2. |
- Oja, Martin, et al.
(författare)
-
Dual Single Pixel Imaging in SWIR using Compressed Sensing
- 2020
-
Ingår i: VISAPP: PROCEEDINGS OF THE 15TH INTERNATIONAL JOINT CONFERENCE ON COMPUTER VISION, IMAGING AND COMPUTER GRAPHICS THEORY AND APPLICATIONS, VOL 4: VISAPP. - : SCITEPRESS. - 9789897584022 ; , s. 48-56
-
Konferensbidrag (refereegranskat)abstract
- In this paper, we present a dual Single Pixel Camera (SPC) operating in the Short Wave InfraRed (SWIR) spectral range that reconstructs high resolution images from an ensemble of compressed measurements. The SWIR spectrum provides significant benefits in many applications due to its night vision capabilities and its ability to penetrate smoke and fog. Walsh-Hadamard matrices are used for generating pseudo-random measurements which speed up the reconstruction and enable reconstruction of high resolution images. Total variation regularization is used for finding a sparse solution in the gradient space. The detectors have been fitted with analog filters and amplification in order to capture scenes in low light. A number of outdoor scenes with varying illumination have been collected using the dual single pixel sensor. Visual inspection of the reconstructed SWIR images indicate that most scenes and objects can be identified with a lower subsampling ratio (SR) compared to a single detector setup. The image quality is consistently better than with one detector, with similar results achieved with fewer samples or better results with the same number of samples. We also present measurements on moving objects in the scene and movements in the SPC unit and compare the results between single and dual detectors.
|
|
