Self-collimated beams and photonic bandgap mirrors in photonic crystals are evaluated for applicability in an on-chip interconnect system. Simulations using the plane-wave expansion and finite-difference time-domain methods are utilized to design and evaluate the theoretical performance of these systems, called a virtual waveguide due to borderless confinement of the signal. The effect of systematic and random fabrication errors on the performance is characterized. Coupling efficiency is virtually unaffected by misalignment, but is found to be a strong function of the length of the waveguide and the frequency of light. Additional routing capabilities of sharp 90/spl deg/ turns and signal crossings with no crosstalk are demonstrated. Photonic crystal virtual waveguides are ideal structures for on-chip optical signal routing.

In the PET system a block detector, which is a position-sensitive photomultiplier (PMT) tube coupled to four arrays of 1.7-mm-wide BGO crystals, is utilized. Fifteen block detectors are positioned to form a 35-cm-diameter ring, with four BGO arrays coupled to each PMT. This provides four detector rings, giving the system a 7-slice imaging capability. The gantry head tilts up to +/-90 degrees , and is capable of moving up and down by 30 cm. These positioning capabilities allow flexibility and great ease of use in subject positioning. A gantry entrance size of 22 cm in diameter allows studies ranging from rats and mice to primates such as Rhesus and squirrel monkeys. The physical performance of the system has been evaluated.