Shaping of phase and amplitude of ultrashort laser pulses with organic spectral hole burning materials
✍ Scribed by Dr. Heinrich Schwoerer; Daniel Erni; Dr. Alexander Rebane; Prof. Urs P. Wild
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 500 KB
- Volume
- 7
- Category
- Article
- ISSN
- 0935-9648
No coin nor oath required. For personal study only.
✦ Synopsis
Merck, dimethyldioctadecylammonium bromide (DOMA) was purchased from Kodak. The amphiphiles were spread from a milliinolar solution in chloroform on the aqueous subphase (Milli-Q water, Millipore) of a Fromherz-type round trough. The surface pressure was measured with a Wilhelmy balance and the surface potential measurements were done with a vibrating plate condenser.
In order to build up the monolayer assemblies, a glass support was first covered with a monolayer of C,,NH, transferred at a constant surface pressure of 20 mN/m to make the Furface hydrophobic. The dye-containing monolayers were transferred onto this glass plate by horizontally dipping it through the air -water interface covered with the dye monolayers at a surface pressure of 20 mN/m. The dye monolayer was then covered with a monolayer of AME at a constant surface pressure of 20 mN/m by vertically lifting the substrate through the air-water interface.
The reflection measurements at the air-water interface were done under normal incidence with a spectrometer as described in [24]. The determination of the chromophore orientation was evaluated from reflection spectra measured under oblique incidence (45"). The experimental set-up and the theory for the analysis of the data is given in [25]. Absorption and fluorescence spectra of the transferred monolaycrs were measured using systems described earlier 126,271. The microscopic optical properties of the transferred LB monolayers were probed with a Brewster angle microscope (BAM 1, NFT, Gottingen, FRG). A self-made sample holder with an electric heating foil was used for heating the samples. The temperature was measured with a Pt 1000 resistor pressed on the surface of the sample. A constant heating rate of 0.2 K/s was maintained by controlling the direct current through the foil.