Abtract 

In this module, we will learn about some experimental methods pertaining to optics and photonics. These are vast fields. Nevertheless, there is a need for hands-on training to become proficient in these areas of research. Such methods can be characterized according to purpose and according to setup. One of the main aims of this module is to learn about lasers and actually how to build lasers. This task will involve learning a variety of concepts including population inversion, gain materials, resonator design, optical alignment, lasing threshold, and spectroscopic characterization of the laser light. The first laser we will build will be an organic laser. Then we will learn how to take a high brightness semiconductor light-emitting diode and construct from it a wavelength tunable diode laser. Included in learning about tunable lasers will be discussions on different configurations as well as the optomechanics required to achieve wavelength tuning. With all of these lasers systems in hand, then second part of this module will cover applications of lasers and other lights sources for spectroscopy. Students will learn about absorption spectroscopy, frequency modulation spectroscopy, and techniques for overcoming noise, such as the lock-in amplification, balanced detection, and homodyne and heterodyne detection. Students will then learn about Raman spectroscopy, micro-Raman, and how to align a Raman microscope. Finally, students will learn how to build their very own high-end Raman system based on tunable lasers for the relatively low cost.

Outline

1. Light-Matter Interactions
2. Lasers: population inversion, gain, and optical feedback
3. Resonator design
4. Lasing threshold and coherence
5. CW vs. Pulsed Lasers
6. Pulsed Lasers: q-switching and mode-locking
7. Building lasers: excitation and optical alignment
8. Diode Lasers
9. Building an organic dye laser
10. Building a tunable diode laser
11. Frequency Locking a laser
12. Spectroscopy
13. UV/VIS absorption, Emission, and Frequency Modulation Spectroscopy
14. Signal to Noise Ratios
15. Sources of Noise
16. Lock-in amplifiers
17. Balanced Detection
18. Interferometery
19. Raman Spectroscopy
20. Micro-Raman spectroscopy
21. Aligning a Raman spectrometer
22. Choosing Raman filters
23. Stimulated Raman Spectroscopy
24. Building a stimulated Raman spectrometer

Learning Outcomes

Students will come away with a thorough understanding of lasing processes, from fundamental physics to the material science of constructing gain layers and semiconductor diode structures, and then photonic device engineering.  In addition to learning about lasers, students will learn how lasers and various other light sources are used to perform spectroscopic characterizations of materials and devices.  Towards this aim, we will learn about absorption and emission spectroscopy and frequency modulation spectroscopy, and the critical topics of noise and detection limits and methodologies to obtain the best signal to noise ratio from a spectroscopic setup.  Students will learn about Raman spectroscopy and how to build a high-performance compact low-cost Raman spectrometer

Bibliography 

Responsible Academic 

Senior Lecturer Yaakov Tischler (BIU)

External Evaluator 

Prof. Michael M. Rosenbluh, BIU, Israel

Awarded ECTS

3