Spectrum white light

To optimize the conversion efficiency, physical focusing conditions need to be optimized. With reference to the SG spectrum shown in Fig. 5.8, for fixed incident laser power and fixed focal length of the lens, the location of the focus point within the 7.5 cm long barium fluoride crystal was found to determine the extent of the white light spectrum. With the focus located f cm inside the crystal, the flattest possible spectrum of white light was obtained (as shown in Fig. 5.8), and the highest conversion efficiency was also achieved. 

Fig. 7 Experimental scheme of a LiNbOs waveguide with an electro-optical interrogation. Here, two electrodes are present, which allow to apply a potential across the electro-optically active waveguide. This leads to a change in the k-vector of the propagating waveguide mode. The transmission of either a single wavelength or a white light spectrum can be measured, as well as the phase between the transmitted single wavelength and a reference beam can be measured...

When metals are burned, they form oxides (AI2O3 and MgO) that may weaken the purity of flame color. This is because their boiling points are so high that they remain as liquid droplets and thus emit a continuous (white light) spectrum. 

The narrow photoluminescence (PL) spectrum of these NCs are widely tunable across the visible spectrum to adjust white light parameters, whereas the conventional yellow phosphorus has a fixed PL spectrum. By using the size effect, these NCs can fully cover the visible spectrum from blue to red as shown in Fig. la-d. Additionally, the small overlap of the NC emission and absorption spectra provides the ability to tune the white light spectrum conveniently. We carefully design and implement hybrid device parameters such as the order and thickness of the NC films and type and density of NCs as necessary to generate white light with the desired characteristics. 

It is the absorption of blue wavelengths in the white light spectrum by these polyene sequences that make degraded PVC surfaces appear yellow. Surface discoloration of PVC cladding (siding) and window frames exposed to sunlight is well known (Edge et al., 2010) and is a result of this reaction. 

Feedback correction must be applied to every sample measurement without operator intervention and without degrading the operating speed of the system. Of the calibration observations that are needed, all except the white-light spectrum need to be recorded simultaneously or nearly simultaneously with every sample measurement. To deal with laser position shift, a Raman-shift standard spectrum can be obtained through the sample channel—more on this later. 

At the start of a measurement session, a white-light spectrum is necessary. The white source can be switched into position under software control. A dark set is automatically recorded and subtracted from the white set. Figure 12A shows a typical result for the two simultaneously recorded stripes of the spectrum obtained with a Kaiser Optical Holoprobe 532 nm system with a duplex grating. For this recording, the white source was placed at the sample position so that the effect of the full collection path was recorded. 

Figure 12 White-light correction of a Raman spectrum recorded on a Kaiser Optical Systems Holoprobe with a duplex grating. The left column shows the low-shift stripe the right shows the high-shift stripe. (A) recorded white-light spectrum (B) true white-light spectrum (C) correction set (D) uncorrected spectrum of neat acetonitrile (E) corrected spectrum of neat acetonitrile.

What is an emission spectrum How does an emission spectrum of a gas in a discharge tube differ from a white light spectrum ... 

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