Thanks

The difference between QW distances DQW in the same structure but different wavelengths is originated from the different couplings. For the same lattice of SM waveguides, the shorter the wavelength, the weaker the evanescent couplings between the nearest cores. As a result, the light takes a longer distance to fully couple from one core to the other. This property would give us another parameter

Wavelength-dependent QWs in DPPL (left) and sixth-order FQPL (right). Both DPPL and FQPL are

As stated earlier, QWs and LQWs are important for many applications in quantum computing and quantum communication. In particular, recent investigations show symmetrical LQWs can be potentially employed for storage and retrieve quantum information for a secure quantum memory. The authors in Ref. [19] have pointed out that symmetrical LQWs are required for quantum memory applications. Because it is impossible to achieve symmetrical LQWs in spatially randomly disordered systems, the authors proposed temporally disordered operations using multiple quantum coins. Furthermore, the concept of localization due to temporally disordered operations has been later expanded to consider multiple quantum coins with quasiperiodic sequences that include Fibonacci, Thue-Morse, and Rudin-Shapiro sequences [37]. Although the idea of employing symmetrical LQWs for quantum memory is very interesting and worthy of further exploration, we would like to stress that experimental implementation of QWs is not simple even with only one quantum coin; therefore the idea of using multiple quantum coin operations

As presented in this chapter, our results show that symmetrical QPLs can be conveniently constructed with quasiperiodic sequences. As a result, symmetrical LQWs can be achieved in the proposed QPLs in general and in particular in FQPLs

to control and optimize the QWs in both PLs and QPLs.

composed of the same A and B waveguides defined above, and both have 39 cores.

Advances in Quantum Communication and Information

would be extremely difficult in practice.

and TMQPLs. The results are significant in two aspects:

4. Conclusions

70

Figure 8.

The authors would like to thank Kam Ng and Tyson DiLorenzo for reading the manuscript.

Advances in Quantum Communication and Information

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