# Design of Novel Fiber Optical Flexible Routing System
## 4 Conclusions  
In this research, an all-optical routing system based on AWGs, optical circulators, couplers and optical switches was used to implement a bidirectional interleaver, OXC, and ROADM with three different functionalities. In the case of the bidirectional interleaver, the even and odd channels implement multiplexer and demultiplexer functions through interleaver processing based on AWG routing rules and the status of the corresponding SWs. The proposed routing system was shown to effectively implement the bidirectional interleaver function. For the proposed routing system, the OXC function can also be tested by using the input odd and even channels. That is, the odd and even channels are exchanged at the output port. In the ROADM verification process, we realized the function of adding and dropping through the bar or cross status of optical switches. We used two optical signal wavelengths (i.e., \(\lambda_{2}\) and \(\lambda_{5}\)) to verify the feasibility of the proposed routing device with ROADM functionality. Based on the numerical experiments of static characteristics, the proposed routing device can effectively implement the routing functions of an interleaver, OXC, and ROADM.  
After simulation analysis, we have determined the feasibility of the proposed router architecture, and then we will conduct actual optical path experiments, including static and dynamic characteristics, to test the performance of the proposed router. In addition, the AWG has a wavelength cycling characteristic of light, so more than eight signal wavelengths can be configured in the proposed routing system. Furthermore, the choice of input signal channel spacing depends entirely on the characteristics of the AWG used. The AWG channel spacing used in this research system is 100 GHz, so the input signal channel uses a 100 GHz spacing. We can change the channel spacing of the input wavelength by using different channel spacing AWGs.  
The biggest difference between our proposed router system and available systems is that we integrate the three functions of ROADMs, an optical interleaver, and OXC, and there is no need to add additional optical components when switching between functions. To the best of our knowledge, currently available products do not have an optical router with these three functions. This investigation provides a more flexible router system for DWDM networks.  
Figure 14: The spectrum at the output port 2 with the add \(\lambda_{5}\) process (odd channel).  
Figure 13: The spectrum at the output port 1 with the add \(\lambda_{2}\) process (even channel).  
**Author Contributions:** Conceptualization, P.-T.W. and T.-C.L.; investigation, P.-T.W. and T.-C.L.; Experiments, P.-T.W.; validation, T.-C.L.; funding acquisition, P.-T.W. and T.-C.L.; project administration, T.-C.L.; writing--original draft preparation, P.-T.W.; writing--review and editing, T.-C.L.  
**Funding:** This research was funded by the Ministry of Science and Technology of Taiwan, grant number MOST 105-2221-E-327-028.  
**Acknowledgments:** The authors would like to thank [PERSON] for drawing the optical routing system configuration diagram and experimental results presented in this paper.  
**Conflicts of Interest:** The authors declare no conflict of interest.