Connection Loss Reduction in Variable Optical Delay Line by Using Graded-Index Type Photonic Crystal Fiber
Citation
Higuchi, K.; Yokota, H.; Yoneya, K.; Imai, Y. (2018). Connection Loss Reduction in Variable Optical Delay Line by Using Graded-Index Type Photonic Crystal Fiber. IEEJ Transactions on Electrical and Electronic Engineering. https://doi.org/10.1002/tee.22624.
Keywords
- Graded-index type photonic crystal fiber (GI-PCF)
- Low loss butt-joint connection
- Periodic beam propagation
- Optical fiber device
- Photonic crystal fibers (PCFs)
- Connection loss reductio
- Variable optical delay line (ODL)
- Air gap
- Mode extent
- Periodic mode change
- Butt-joint connection
- Mode mismatch
- Beam propagation method (BPM)
- LP01 mode
- Effective refractive index
- Parabolic distribution
Brief
This article proposes using a graded-index photonic crystal fiber (GI-PCF) to periodically vary the optical mode extent, thereby significantly reducing the butt-joint connection loss between photonic crystal fibers (PCFs) with an air gap.
Summary
This paper proposes using a graded-index photonic crystal fiber (GI-PCF) to reduce connection loss between standard photonic crystal fibers (PCFs), especially when there's an air gap. The GI-PCF has a parabolic distribution of air hole diameters, causing the light beam (mode extent) to periodically change as it travels through the fiber. By choosing the right length of GI-PCF (e.g., 20.6 mm), the beam exiting it can be shaped to better match the mode of the receiving PCF after propagating through an air gap (e.g., 200 μm). Numerical analysis shows that this method can reduce the connection loss from 3.5 dB (without GI-PCF) to . The periodic mode variation in the GI-PCF, mainly due to interference between LP01 and LP11 modes, allows for this mode size adaptation. This technique is relevant for applications like variable optical delay lines that may involve air gaps in PCF connections .
Origin: https://sci.bban.top/pdf/10.1002/tee.22624.pdf#