The Fiber Optic Ratio Calculator helps engineers and technicians understand how light travels through fiber optic cables. It calculates important values like numerical aperture, acceptance angle, and sometimes the core-to-cladding ratio. These values show how much light a fiber can accept and guide, which affects signal strength and quality. This tool is part of the Optical Communication Calculator category and is useful in designing fiber optic networks, medical devices, and communication systems.
formula of Fiber Optic Ratio Calculator
- Numerical Aperture (NA):
NA = sqrt(n_core² − n_cladding²)
Where:
n_core is the refractive index of the fiber core
n_cladding is the refractive index of the fiber cladding
- Acceptance Angle (θ):
θ = arcsin(NA)
This angle shows how wide the cone of light can be for it to enter and travel through the fiber.
- Core-to-Cladding Ratio (optional):
This ratio tells how big the fiber’s core is compared to the whole fiber diameter.
Core-to-Cladding Ratio = Core Diameter / Cladding Diameter
Example:
For a standard single-mode fiber with an 8 microns core and 125 microns cladding:
Ratio = 8 / 125 ≈ 0.064
Common Fiber Optic Terms and Reference Table
This table shows average values for different types of fibers and helps you compare your results quickly.
| Fiber Type | Typical Core (µm) | Cladding (µm) | Core-to-Cladding Ratio |
|---|---|---|---|
| Single-mode Fiber | 8–10 | 125 | ~0.064 |
| Multi-mode Fiber | 50–62.5 | 125 | ~0.40 |
| Plastic Optical Fiber | 980 | 1000 | ~0.98 |
This table can help pick the right fiber type for your project.
Example of Fiber Optic Ratio Calculator
Let’s check an example for a single-mode fiber:
Given:
n_core = 1.4682
n_cladding = 1.462
- Calculate NA:
NA = sqrt(1.4682² − 1.462²)
NA = sqrt(2.1556 − 2.1381)
NA = sqrt(0.0175)
NA ≈ 0.132 - Find Acceptance Angle:
θ = arcsin(0.132)
θ ≈ 7.58 degrees - Core-to-Cladding Ratio:
Core Diameter = 8 µm
Cladding Diameter = 125 µm
Ratio = 8 / 125 ≈ 0.064
This shows the fiber accepts a small cone of light, which keeps the signal focused for long distances.
Most Common FAQs
The numerical aperture shows how much light can enter the fiber. A higher NA means the fiber can gather more light but might lose signal quality over long distances.
The acceptance angle tells how wide the light beam can be to enter the fiber and stay guided inside. It helps when aligning light sources with fibers.
A larger core-to-cladding ratio means the fiber can carry more light and supports multiple light paths. This is common in multi-mode fibers for short-distance, high-bandwidth uses.