1. In the name of God Photonic crystals created by holography Raheleh Mohammadpour

2. Photonic crystals Photonic crystals are microstructured materials which have periodic dielectric constant.

3. Photonic Band Gap

4. Comparison Semiconductors Energy band gaps Periodic crystal potential Atomic length scales Control electron flow Photonic crystals Photonic band gaps Periodic dielectric constant Length scale ~ Control wave propagation

5. Experimental setup

6. Holographic lithography

7. Intensity Pattern G mn(m,n=0,…,3) are reciprocal lattice vectors.

8. Holographic lithography ‏‏ The light is bright in the polymer make that part insoluble. In the dark regions of the interference pattern the polymer remain unchanged.

9. 3-D photonic crystal The structure of polymer atoms connected by polymer bonds and surrounded by air voids.

10. 1-D Photonic crystal 1-D photonic crystal (grating) formed by laser holography

11. 2-D photonic crystal 2-D photonic crystal fabricated by laser holography

12. Consequence The holographic technique has the advantage of speed since the entire pattern in the photoresist is created in nanosecond. A variety of crystal structures can be created by varying the orientation and polarization of the beam lasers.