1. Laser beam expansion: This technique is often needed in optics experiments. In this experiment, we use a negative lens and a positive lens to form a confocal telescopic system. Expansion ratios of different focal-length combinations are verified in the experiment. 

 

2. The knife-edge technique is a classic means for measuring the focal length of a lens. A unique knife-edge assembly is designed for measuring the focal lengths of several positive lenses. 

 

3. Single-lens imaging: This part of the experiment verifies the imaging formula of a thin lens. Magnification ratios of different object and image distances are measured. 

 

4. Measurement of the focal length of a negative lens: This part of experiment is accomplished by imaging the virtual image formed by the negative lens through a positive lens with a known focal length. The focal length of a negative lens is deduced from successive uses of the single-lens imaging formula. 

 

5. A lens system: A two lens setup is used to illustrate the concept of a lens system. Locations of the cardinal planes are measured for this lens system.