Experiments during Sommersemester 2023
Room: 02.119 ZAQant
E-Mail: ruoming.peng (at) pi3.uni-stuttgart.de
Room: 1.535 Tel.:
When light hits matter it gets scattered. Mostly this happens in form of elastics scattering (Rayleigh scattering), where the molecule almost instantly reemits the entire absorbed photon energy with the same frequency. However the excited molecule can absorb (or emit) a (small) part of the photon energy e.g. as molecular vibrations and emit light with a smaller (or larger) frequency. This is called Raman-scattering. The Raman spectrum is characteristic for each molecule and each crystal. From the energy difference to the incident light and the polarization degree of the scattered light and with the help of group theory one can gain informtation on the atomic structure of the samples. The selection rules for Raman- and IR spectroscopy differ in a way that both methods complement each other very well. In the experiment the Raman spectra of CHCl3, CHBr3, CdCl3 und CdBr3 are measured. In the setup the light from a HeNe-Laser scattered off the sample is analyzed with a spectrometer. For the evaluation the measured Raman spectra are compared for these molecules with group theory and assigned to their corresponding group. The Boltzmannn contstant is determined from the intensity ratio between Stokes- and Antistokes lines. Keywords: Raman transitions (Stokes and Antistokes), vibrational spectroscopy, group theory of simple symmetries
Room: 02.032 ZAQant
E-Mail: yong.lu (at) pi3.uni-stuttgart.de
Room: 1.572 Tel.: 64848
Tel.: +49 711 685 69685
E-Mail: nicolas.dumerat (at) igvp.uni-stuttgart.de
Room: PI 218 Tel.: 2480
Over 99% of visible matter in the universe exists in plasma state. On earth natural occurring plasmas are only found in the upper layers of our atmosphere or in natural lightnings. First since the 1920s the research group of Irving Langmuir has devoted themselves to the scientific investigation of plasmas that were generated in the laboratory. Langmuir coined the term “plasma”. In this experiment the work with one of the most important diagnostic tools in plasma physics, the Langmuir-probe, is learned. Two different types of probes are used, the single and the double probe, in order to study the plasma parameters of a glow discharge dependent on different discharge parameters. With the Langmuir-probe a number of fundamental properties of a plasma that distinguish it from the other states of matter can be illustrated.
E-Mail: rkgupta (at) pi5.physik.uni-stuttgart.de
Room: 1.519 Tel.: 64813
Today nuclear magnetic resonance (NMR) is one of the most important spectroscopic methods in physics, chemistry, biology and medicine. It provides information about the electronic environment of single atoms and their interactions with neighbouring atoms. This information allows the analysis of the structure and dynamic of the sample. The measuring principle of cw- and pulsed NMR is shown with a simple spectrometer. The characteristic values T1 (spin-lattice relaxation time) and T2 (spin-spin relaxation time) are determined for selected samples.
classical and quantum mechanical description of nuclear magnetic resonance, pulse-NMR (rotating coordinate system, FID, spin echo, pulse sequences), measurement of T1 and T2 (spin-spin relaxation, spin-lattice relaxation)
E-Mail: sreehari.jayaram (at) pi3.uni-stuttgart.de
Room: 1.911 Tel.: 64872
In this experiment, the basics of nuclear magnetic resonance imaging (NMR imaging) are taught. In the first part of the experiment, a basic understanding of generating an NMR signal, optimizing this signal, and extracting the information contained therein is developed.
In the second part of the experiment, different imaging methods are used, and advantages and disadvantages as well as theoretical and technical limits are explored.
E-Mail: lavoine (at) pi5.physik.uni-stuttgart.de
Room: 1.543 Tel.: 64867
In this students’ lab a simple He-Ne-Laser is aligned for different output mirrors.The stability ranges for different resonator arrangements and the laser gain are determined. Also the axial development of the laser beam is visualized by a CCD camera and will be measured. By different frequency selective optical elements inside the resonator the laser is operated at different wavelength. The output wavelength is thereby determined by a CCD spectrometer. The axial modes of a He-Ne-Laser will be examined with a Fabry-Pérot-Interferometer. Key words Laser conditions, laser types, 2-,3-,4- level laser, stimulated and spontaneous emission, absorption, line broadening mechanism, laser modes, free spectral range, finesse, axial and transversal modes, Fabry-Pérot-Interferometer.
E-Mail: san-lam.ng (at) pi3.uni-stuttgart.de
Room: 1.939 Tel.: 64864
In a measurement, the demanded information is often given in a time-dependent voltage signal, in the so called time domain. With an oscilloscope, you can record these signals. However, the desired information is often coded in frequency, so one is only interested in particular frequencies. With the aid of a spectrum analyser, the desired signals can be visualized in the frequency domain. Using examples of simple physical experiments (acoustic resonator, coupled oscillator, fluxgate magnetometer), the experiment demonstrates the versatile possibilities of Fourier methods. Where the oscilloscope just detects noise, you can detect signals in the Fourier space, which differ in amplitude by a factor of 10.000. Aside, a spectrum analyser is excellently qualified for analysing amplitude- or frequency-modulated signals or for the characterisation of nonlinearities.
E-Mail: jzhao (at) pi5.physik.uni-stuttgart.de
Room: 1/519 Tel.:
Imaging techniques are among the most important research methods in science. In order to interpret the images obtained, however, one must have understood the physics on which the image contrast is based. This experiment will familiarize you with the basics of optical microscopy. To do this, you will gradually build your own microscope from simple components and use a modern CCD camera to analyze the contrasts that are characteristic of the various illumination and imaging techniques. Keywords: Lenses and lens errors, Fourier optics, Koehler illumination, conjugate planes, Abbe imaging theory, point spread function, contrast transfer function, bright field, and dark field imaging, Zernike phase contrast, fluorescence microscopy, CCD camera.