PPT Laser florcent Induced Spectroscopy(bittu).pptx

spectroscopy is used to detect properties of light

1. Review on Advancement of Laser Induced Fluroscence Spectroscopy Submitted by: Name : Bittu Kumar University Enroll :200130302005 Course Major :Project (5502) Program :MSc Physics Submitted to : Mentor : Ms. Jagriti Gaba Designation : Assistant Professor Department : Physics Major Project (5502)

2. INDEX INTRODUCTION OF LIFS HISTORY OF LIFS DESIGN OF LIFS WORKING OF LIFS TYPES OF LIFS APPLICATIONS OF LIFS ADVANTAGES OF LIFS LIMITATIONS OF LIFS IN PRESENT PROSPECTIVE IN FUTURE PROSPECTIVE CONCLUSION REFERENCES

3. INTRODUCTION OF LIFS Fluorescence is a process involving the emission of light from any substance in the excited states. Spectroscopy is  the study of the absorption and emission of light and other radiation by matter . A laser is  a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation .  Laser Induced Flourscence Spectroscopy is a type of technique by which a sample (Atoms or Molecules ) gets into excited state with the help of laser and the fluorescence gets emitted by the sample . Fluorescence is the emission of electromagnetic radiation (light) by the substance absorbed the different wavelength radiation. Its absorption and emission is illustrated in the below diagram

4. PHOTON EMISSION

5. Energy levels will tell us about :- 1) The optical pumping transition 2)Configuration for population inversion 3)laser emission wavelength 4)Gain bandwidth.

6. HISTORY OF LIFS The era of modem spectroscopy began with the invention of the laser, which provides intense, collimated monochromatic radiation throughout optical spectral range.  The first prototype , the ruby laser , a pulsed solid state laser emitting red light at a wavelength of 0.694 µm, was developed by T.H. Maiman in 1960, and the He-Ne laser, a continuous-wave gas laser emitting infrared light at 1.15 µm, was developed shortly afterwards by A. Javan .

7.   The dye laser , developed by P.P. Sorokin, F.P. Schafer, B.B. Snavely and others in 1966, is of particular significance because it provides monochromatic radiation that can be broadly tuned over the visible spectral range. Laser light, with its high intensity, narrow spectral linewidth and phase coherence, immediately stimulated new interest in atomic and molecular spectroscopy.  Laser light opened the field of ultra-high resolution spectroscopy. Laser light also opened the possibility of conducting spectroscopy in the time domain . LIF spectroscopy  was first developed by Richard Zare in 1968 for the detection of atoms and molecules in the gas phase.  HISTORY OF LIFS

8. DESIGN OF LIFS

9. WORKING OF LIFS They mainly consists of four parts: light sources, Monochromators , Optical filters and Detector. Light sources that can emit wavelength of light over the ultraviolet and the visible range can provide the excitation energy. Prisms and diffraction gratings are two mainly used types of Monocharomators , which help to get the experimentally needed chromatic light with a wavelength range of 10 nm . Monocharomators are evaluated based on dispersion, efficiency, stray light level and resolution. Optical filters are used in addition to monochromators in order to further purifying the light. An InGaAs array is the standard detector used in many spectrofluorometers . It can provide rapid and robust spectral characterization in the near-IR.

10. TYPES OF LIFS There are basically Two different kinds of spectra exist, 1)Disperse spectra 2)Excitation spectra Disperse spectra   The disperse spectra are performed with a fixed lasing wavelength and the fluorescence spectrum is analyzed. Excitation spectra Excitation scans on the other hand collect fluorescent light at a fixed emission wavelength or range of wavelengths. Instead the lasing wavelength is changed.

11. APPLICATIONS OF LIFS Analysis of Carbon and Alloying elements in Cast Iron . Elemental mapping of Marcellus shale core samples . Quantification of sintering Aid in Optical Ceremics . Chemical imaging of Ruby-in- Zoisite Gem rock . Geochemical fingerprinting of coltan minerals (the elements niobium and tantalum are extracted ) . Rapid analysis of Pb (Lead) of thin solder plating on semiconductor . Considering food applications, it has currently been demonstrated for the screening of products on basis of their chlorophyll concentration . The detection process of the objects present in food is being done by just comparing flouroscence spectra of foods and objects. For green foods , the distinction can be done by comparing the glasses in green and the chlorophyll flourscence intensity.

12. ADVANTAGES OF LIFS First, LIF has excellent detection sensitivity because a signal is observed against a dark background. Second, the emitted radiation can be collected at various angles with respect to the collimated laser beam, making it possible to obtain two- and three-dimensional images. Third, LIF imaging of translucent and opaque materials is particularly attractive due to the strength of the resonant absorption process compared with the non-resonant Rayleigh techniques in Raman spectroscopy. Fourth, by dispersing the fluorescence, it is also possible to learn about the transitions from the excited state to various lower energy levels of the fluorescent molecule.

13. Fifth, because of the delay between the excitation and detection events, it is possible to study the processes the excited molecule undergoes in the intervening time Extremely fast measurement time, usually a few seconds, for a single spot analysis An advantage over absorption spectroscopy is that it is possible to get two- and three-dimensional images since fluorescence takes place in all directions (i.e. the fluorescence signal is usually isotropic). The signal-to-noise ratio of the fluorescence signal is very high, providing a good sensitivity to the process. LIF is useful in the study of the electronic structure of molecules and their interactions. ADVANTAGES OF LIFS

14. IN PRESENT PROSPECTIVE Detection of purity - Detection of Viruses in Wastewater Using LIF One of the most important aspects in controlling a viral outbreak is monitoring the number of infected people in a population. It can be used for determining the residual contamination in the ground water. This method allows outbreaks to be predicted weeks in advance without delays in getting the total population tested. Optical tumor diagnosis Detection and quantification of biomolecules and biological processes ( DNA sequencing, trace protein analysis, polymerase chain reaction products, and single-cell analysis) Virological analysis LIF has been used for many years for the analysis of paint

15. IN FUTURE PROSPECTIVE A single-photon LIF sensor was recently developed for atmospheric measurements of nitric oxide (NO) in the atmosphere. Rapid tuning of a narrow-band laser on and off of a rotationally resolved NO spectral feature near 215 nm and detection of the red-shifted fluorescence provides for interference-free direct measurements of NO with a detection limit of 1 pptv for 1 s of integration, or 0.3  pptv for 10 s of integration. The instrument has been deployed on the NASA DC-8 aircraft and provided more than 140 h of NO measurements over 22 flights autonomously .

16. CONCLUSION Fluorescence Detection of Transition Metal Oxide Nanoparticles such as Al2O3, CeO2, CuO , Fe3O4, Mn3O4, TiO2, ZnO , ZrO2 are used as biomedical materials in biosensing , dentistry, diagnosis, immunotherapy, regenerative medicine, tissue therapy, and wound healing. The advances in laser, detector, fiber optics, and fluorescent labeling technologies have transformed a technique that was once difficult to use, and limited in its scope, into one of the most prominent detection and imaging techniques. In addition, as the fields of biology and biochemistry have advanced, the needs for fluorescence detection has dramatically increased, further increasing demand for LIF.

17. REFERENCES https://www.thermofisher.com/ca/en/home/life-science/cell-analysis/cell-analysis-learning-center/molecular-probes-school-of-fluorescence/fluorescence-basics/overview-filters-light-sources.html#:~:text=1)Themostpopularsources,varyingintensityacrosst https://www.nasa.gov/topics/technology/features/formaldehyde-track.html https://web.mit.edu/spectroscopy/history/history-modern.html 1 https://www.seika-di.com/en/measurement/principle_of_lif.html 2 https://www.edinst.com/blog/what-is-laser-induced-fluorescence/ 3 https://en.wikipedia.org/wiki/Excited_state 4 https://en.wikipedia.org/wiki/Excited_state#/media/File:CuO2- plane_in_high_Tc_superconductor.png 5 https://chem.libretexts.org/Bookshelves/ Analytical_Chemistry / Physical_Methods_in_Chemistry_and_Nano_Science _(Barron)/01%3A_Elemental_Analysis/1.11%3A_Fluorescence_Spectroscopy 6 https://www.researchgate.net/figure/a-i-Photograph-and-ii-schematic-of-the-fluorescence-detection-apparatus-used-in_fig3_259608902 7 https://www.researchgate.net/figure/Scheme-of-laser-induced-fluorescence-spectroscopy-LIFS-systems-Drop-TM-8000-Thermo_fig1_267568222 8 http://appliedspectra.com/applications/application-notes.html 9 https://en.wikipedia.org/wiki/Laser-induced_fluorescence#:~:text=2%20Applications-,Types,wavelength%20or%20range%20of%20wavelengths 10 https://www.sciencedirect.com/topics/chemistry/laser-induced-fluorescence-spectroscopy 11 https://link.springer.com/content/pdf/10.1007/s11434-013-5826-y.pdf 12 https://www.mdpi.com/2227-9040/9/10/275/pdf 13 https://www.newport.com/n/laser-types