Chapter 17 - Optical Receiver 127
106 V3.2
Figure 17-5 Poor physical contact because of dust particles
The microscope image in the measuring receiver shows a large magnification of the optical fiber
(Figure 17-6). That figure is taken with Lightel DI-1000 USB microscope with an optical
magnification of 200. The core of the optical fiber is visible in the center.
Figure 17-6 Microscope zooming
Typical requirements for single-mode fibers:
Zone name (diameter)
Scratches
Damage
A: Core (0-9 µm, 0-25 µm)
Non permitted
Non permitted
B: Cladding (25-120 µm)
No limits
all < 2 µm
5 in 2 – 5 µm range
None > 5 µm
C: Adhesive (120-130 µm)
No limits
No limits
D: Contact (>130 µm)
No limits
No limits
