Page 2 of 5 1 EE176 Midterm Exam // Student Name: Student ID# (OPEN BOOKS AND NOTES - NO INTERNET ACCESS) (1) Suppose that you are operating a laser which lases at =1.5 m. The beam waist of this laser is 10 m. (a) 5 pts - Calculate the beam diameter of this laser after 10 m of propagation in air from the location of the beam waist. Assume that the laser beam is a Gaussian beam. (b) 10 pts - Calculate the distance(s) from the beam waist that the radius of curvature is maximum and minimum. (c) 5 pts - What is stimulated emission? Briefly explain its relationship to Lasers. 2 (2) 10 pts- Explain how a fluorescence microscope works. Draw its optical system and briefly explain. 5 pts- How can one use fluorescence microscopy to recognize and count specific cell types (in e.g., blood)? 5 pts - How can one use or modify fluorescence microscopy to beat the diffraction limit of light? 3 (3) 10 pts- How does a Near-field Scanning Optical Microscope (NSOM) work? Draw its optical set-up and briefly explain. Mention one advantage and one disadvantage of NSOM imaging systems in general. What does spatial resolution