1. Resolving Power:
The resolving power of a device is the minimum linear separation (s ) ,or angular separation (), between two resolvable objects observed by that device

2. Resolving power of human eye:
Θ ~ radian
 smaller, means better device

3. Factors affecting Resolving Power:
Quality of the lens
Chromatic aberration
Spherical aberration
Diffraction of wave

4. Diffraction at a circular aperture: Sin θ = (1.22) / D θ = (1.22)/D
Diffraction at a narrow slit:
Sin θ = /d if θ small, θ = /d
Diffraction at a circular aperture:
Sin θ = (1.22) / D θ = (1.22)/D

6. circular lens ~ circular aperture
light diffracts when it passes through a lens of an optical device

7. The diffraction patterns of the two point sources overlap:
difficult to resolve them.

8. The Rayleigh criterion
Two objects are just resolvable when the first minimum of one diffraction patterns falls on the central maximum of the other.

10. For circular aperture, the minimum angular separation of two resolvable objects is

11. Verify resolving power of human eye

12. Increase D but very limited: D  10m Decrease 
How to increase resolving power (decrease ) of a device?
Increase D but very limited: D  10m
Decrease 

13. Visible:  ~ 10 −7 m , observe bacterium, virus
Use matter wave:  of a electron ~ 10 −10 m, observe simple molecules, atoms

14. Transmission electron microscopes (TEM)
The transmission electron microscope (TEM) uses electron beams of short wavelengths instead of visible light.

16. Salmonella bacteria (沙門氏菌)
E. Coli (大腸桿菌)
Salmonella bacteria (沙門氏菌)

17. Summary:
Definition of resolving power
Factors affection resolving power of a device
Use matter wave to increase the R.P.
Structure of TEM