What is the impact of the drop test on the internal structure of the splitter?
The drop test, a crucial experimental method for evaluating the shock resistance of an Optical Splitter, is primarily employed to simulate the instantaneous mechanical impacts that a device may encounter during transportation, installation, and routine maintenance. The instantaneous high gravitational acceleration (typically measured in multiples of the acceleration due to gravity, g) generated during a drop imparts complex physical stresses on the internal microscopic and macroscopic structures of the optical splitter. The primary physical impacts manifest across the following four key dimensions:
1. Micro-Shear and Displacement at Optical Coupling Alignment Interfaces
In Planar Lightwave Circuit (PLC) splitters, the alignment between the input/output Fiber Array (FA) and the PLC waveguide chip requires sub-micrometer precision (typically below \ < 0.5\ \mu\text{m}). These precision components are usually bonded with specialized UV-cured optical adhesives.
The violent deceleration from a drop generates immense instantaneous shear forces. If these forces exceed the shear strength of the bonding interface, they can cause physical displacement at the micrometer or even sub-micrometer level. This microscopic misalignment can lead to a significant increase in the device’s Insertion Loss (\text{IL}) and severely degrade channel uniformity.
2. Micro-Cracking and Delamination of Optical Adhesives
Inside the splitter, various materials with different Coefficients of Thermal Expansion (CTE) and mechanical properties, such as quartz glass, single-crystal silicon, metal, and polymers, are integrated. The instantaneous shock wave from a drop creates intense stress concentrations at the interfaces between these dissimilar materials. Due to the inherent mechanical brittleness of cured polymer materials like optical adhesives, high-intensity mechanical impacts can easily induce micro-cracking or even localized delamination within the adhesive layer, leading to optical path failure.
3. Micro-bending and Macro-bending Losses in Internal Redundant Fibers
Within the optical splitter’s package, a certain length of bare or tight-buffered fiber is typically retained for splicing buffer and pigtail loops. During a severe mechanical drop, if there is inadequate internal fixation or cushioning, these fibers will undergo violent displacement due to inertia, forming macro-bends with extremely small radii or localized micro-bends. This not only instantaneously increases bending loss due to optical leakage from the cladding but can also lead to fatigue fracture at the bend points due to micro-crack propagation over the long term.
4. Stress Damage and Micro-fractures in Brittle Substrate Materials
Key optical components such as PLC waveguide chips and V-groove substrates are primarily made from typical brittle materials like high-purity quartz glass or single-crystal silicon. In packages without adequate shock absorption design, mechanical shock waves can directly transmit to these brittle components. At the edges, corners, or micro-machined features of these components, micro-fractures, often invisible to the naked eye, are highly likely to occur due to stress concentration. This typically becomes a fundamental underlying cause for device failure in subsequent environmental reliability tests (such as temperature cycling and damp heat aging).
OFSCN® Related Products
For industrial-grade, high-reliability applications and optical fiber sensing expansion needs, Beijing Dacheng Yongsheng Technology Co., Ltd. offers OFSCN® Optical Fiber Splitter.
Standard specifications for this product include 16x32 splitters, 8x16 splitters, 4x8 splitters, and 32x64 splitters. In large-scale engineering projects, it is primarily used to complement OFSCN® Fiber Grating demodulators. Through stringent wavelength design, it can expand a single physical channel into multiple logical channels, thereby optimizing the distribution of measurement points. This product employs a highly reliable, impact-resistant packaging process, ensuring mechanical stability in vibration and shock environments.
The standard product image is shown below:
