Graduate Student, Materials Science and Engineering

B.S. 2002, Materials Science and Engineering, National Tsing Hua University, Taiwan

Office:
4115 MSEB

Telephone: 217-244-2460
E-mail: ychen15@uiuc.edu

 

High quality Holographic photonic crystals

Holographic lithography has attracted great interest among the various methods of 3D photonic crystals fabrication. It is versatile for constructing crystals with different symmetry and basis. The fabrication method is to generate 3D periodic interference patterns with coherent laser beams, then use photoresist to record the patterns (Fig.1). The resulting crystal is large-area, defect free. The size of the crystal can be easily scaled up without increasing processing time (Fig.2).

To obtain a photonic band gap, it is necessary to have high enough refractive index contrast. Therefore the polymer-air crystal created by this process often serves as a template and inverted into high dielectric constant materials such as silicon, which can be created by chemical vapor deposition (CVD).

Incorporating controlled defects into photonic band gap materials can lead to many attractive applications such as optical cavities and waveguides. Although the holographic technique cannot inherently create defects, incorporating two-photon polymerization technique allowed us to do so. In two-photon polymerization, excitation only occurs at the focal point when two photons are absorbed simultaneously, allowing arbitrary 3D writing by polymerization. This can be done by either writing into the same photoresist or by infiltration of a triacrylate photoresist system. (Fig. 3 & Fig. 4)

We are interested in fabricating functional holographically based photonic structures and studying their optical properties and comparing to prediction.

 

People

• Prof. Pierre Wiltzius
• Dr. Masao Miyake
• Dr. Joe Geddes
• Robert Barry
• Andrew Brzezinski
• Christy Chen
• Sidhartha Gupta
• Vinayak Ramanan
• James Rinne