Red-shift or blue-shift spectra

Red-shifted vs. blue-shifted absorption and emission spectra

- A spectral shift towards higher wavelengths (i.e. lower energy and lower frequency) is called a red-shift or a bathochromic shift.

- A spectral shift towards lower wavelengths (i.e. higher energy and higher frequency) is called a blue-shift or hypsochromic shift.

Perform spectral shifting using a|e

Spectral shifting (i.e. moving the spectrum to lower or higher wavelengths) may sometimes be necessary post-acquisition, e.g. when decomposing spectra into individual components subjected to hypso- or bathochromic shifts in different samples.

1. Activate the 'Modify spectra manually' toggle button in the toolbar. This will activate a spectrum selection popup-menu and a shift wavelength editbox.

2. Select the spectrum to be shifted from the spectrum popup-menu. The data from this spectrum is shown in the editable data table.

3. To shift the spectrum, set a value (in nm) in the 'Shift wavelength' editbox and press either the '<-' or '->' button corresponding to a blue-shift and red-shift, respectively. In this example, a data cursor is marked on the spectrum simply to monitor the shift action.

4. Pressing the '<-' button will shift the spectrum to the left, in this example 50 nm.