Overview
IEC 61300-3-21:2019 specifies a standardized method to measure switching time and related performance parameters of a fibre optic spatial switch when actuation energy is applied or removed. This third edition is a technical revision that clarifies definitions and diagrams, removes redundant overlap with IEC 60876-1, and generalizes the permitted detection apparatus beyond just oscilloscopes. The document defines measurement setup, apparatus requirements, and timing definitions used to quantify switch dynamic behavior.
Key topics and technical requirements
- Scope of measurement
- Time-resolved measurement of output optical power referenced to the instant actuation energy is applied or removed.
- Terms and definitions
- Latency time, rise time, fall time, bounce time, and combined switching time (from isolated→conducting and conducting→isolated) with precise definitions and measurement thresholds (10 % / 90 % levels).
- Apparatus and performance
- Optical source (S): stable output and appropriate wavelength/spectral width per the relevant specification (see IEC 61300-3-4).
- Detector (D): fast response - detector response time should be ≤ one-tenth of the rise/fall time to be measured; linearity better than 0.05 dB across expected power; measurement system return loss recommended ≥ 30 dB. Multiple detectors allowed for simultaneous ports.
- Actuation energy supply (AS): electrical/optical drive rise and fall times should be ≤ one-tenth of the switch rise/fall time; duration long enough to capture bounce behavior for non-latch switches.
- Data acquisition system (DAS): must record time-dependent optical power synchronized to actuation; oscilloscope or other DAS (including data-logging optical power meters) is acceptable.
- Termination (T): techniques to suppress reflections (e.g., APC connectors often achieve > 60 dB return loss).
- Procedure and reporting
- Measurement setup per standard diagrams, synchronized triggering, and specification of environmental and launch conditions. Details to be specified are listed for reproducibility.
Applications and users
- Manufacturers of fibre optic spatial switches validating dynamic performance for product datasheets.
- Test laboratories and QC teams performing acceptance, production or conformance testing.
- System integrators and designers assessing suitability of switches for fast reconfiguration in optical networks, data centers, or sensing systems.
- Procurement and compliance groups requiring standardized test evidence of switching time and related parameters.
Keywords naturally integrated: switching time, performance parameters of a fibre optic spatial switch, actuation energy.
Related standards
- IEC 61300-1 - General and guidance for basic test and measurement procedures
- IEC 61300-3-4 - Attenuation measurements (optical power stability)
- IEC 60876-1 - Definitions for optical switch timing (overlap removed in this edition)