A new type of laser radar system with off-axis parabolic rotating surfaces and a hyperbolic plane-convex lens configuration is designed in this paper. Three dimensional vector theory of reflection and refraction are utilized to design and analyze the structural parameters of the system. Ray tracing simulation are performed and results show that the new system can greatly decrease energy loss which is caused by central reflection from the secondary reflector in cassegrain-type antenna. In ideal conditions, the divergence angle of the transmitting rays can be compressed to 0.04 mrad. The incident lights will converge to the fiber core if the incident angle is less than 0.65 μmad. This design provides a practical way to improve performance of laser radar system.
We propose a hollow-core photonic bandgap fiber (HC-PBGF) with background composed of two materials to support orbital angular momentum (OAM) modes. Numerical models are set up to figure out the effective indexes and confinement losses over 1.3-2.0 μm. Simulation results show that this fiber can support more than 48 OAM modes, of which the effective indexes satisfy the condition for effective index separation (<10-4) and the confinement loss keeps under 10-7 dB/m over 1.3-2.0 μm. According to the comparison between fibers with same structure but comprising one or two background materials, adopting two materials to compose background is an effective method to significantly improve the performance of OAM-supporting HC-PBGF. The HC-PBGF proposed here is competitive in dealing for OAM multiplexing for optical communication systems.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.