Wie werden „Rand-Kratzer“ klassifiziert?

OFSCN Globales Technisches Zentrum OFSCN Technische Wissensdatenbank
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Was sind die Bereiche A, B und C? Wo sind die tiefsten Kratzer am schädlichsten?

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In optical communication and optical sensing engineering, the cleanliness and scratches of connector end faces are typically graded and quantitatively inspected according to the International Electrotechnical Commission standard IEC 61300-3-35. To accurately assess end-face damage, the microscopic inspection system divides the end face into several concentric circular areas, using the physical center of the fiber as a reference:

I. Definition and Division of Zones A, B, and C

Taking the most common standard single-mode fiber connector (cladding outer diameter 125\ \mu\text{m}) as an example, the end-face areas are defined as follows:

  1. Zone A: Core Zone

    • Range: Central circular area with a diameter of 0 \sim 25\ \mu\text{m}.
    • Physical Significance: This area covers the optical core of the single-mode fiber (actual guiding core diameter is approximately 9\ \mu\text{m}, mode field diameter is approximately 9.2 \sim 10.4\ \mu\text{m}) and its adjacent electromagnetic field extension region. The absolute majority of the optical signal energy is transmitted within this area.

  2. Zone B: Cladding Zone

    • Range: Annular area with a diameter of 25 \sim 115\ \mu\text{m} (or 25 \sim 120\ \mu\text{m} in some standards).
    • Physical Significance: Covers most of the pure silica cladding area, primarily serving to confine light within the core through total internal reflection and provide mechanical support.

  3. Zone C: Adhesive Zone

    • Range: Annular area with a diameter of 115 \sim 135\ \mu\text{m} (or 120 \sim 130\ \mu\text{m}).
    • Physical Significance: The transitional gap between the outer wall of the fiber’s quartz glass and the inner bore of the ceramic ferrule, typically filled with cured epoxy resin, which serves to position and fix the bare fiber.

(Note: Beyond Zone C, the area with a diameter of 130/135 \sim 250\ \mu\text{m} is Zone D: Contact Zone, representing the surface where the two ceramic ferrules make physical contact during mating.)

II. Where Are Scratches Most Critical?

Scratches in Zone A (Core Zone) are the most critical.

In the IEC 61300-3-35 acceptance specification, the most stringent **