In a transceiver test line the expensive part is the instrument: BER testers, optical spectrum analyzers, oscilloscopes and power meters. An optical switch lets several devices under test, or several test stations, share those instruments under software control, so the line tests more modules per instrument and nobody has to re-plug fibers by hand. The right switch depends on how the paths need to be connected.
Three architectures
- 1×N switches connect one instrument port to one of N fibers. They suit sequential testing: one source or detector shared across many devices. The 7202 motor optical switch documents 1×N configurations with up to 128 channels and a parallel control interface.
- N×M cross-connects (OXC) connect any input to any output, so several instruments and several devices can be paired freely. The OXC N×M documents 4×4 to 64×64 configurations in a 2U chassis, and the 7221 rack OXC documents 16×16, 32×32 and 48×48.
- MEMS switches use micro-mirrors. The MEMS cross-connect documents ≤5 ms switching, ≤2.0 dB insertion loss at 1550 nm and at least 10⁹ switching cycles, for 4×4 and 8×8 configurations (M+N ≤16).
The figures that matter
- Insertion loss: it is added to every measured path and must be inside your calibration. OXC N×M documents ≤2.6 dB at 32×32 and ≤3.0 dB at 64×64.
- Switching time: it sets how much test time is lost between devices. Documented values range from ≤5 ms (MEMS) and <20 ms (OXC N×M) to 30 ms typical (7221).
- Durability: a production line can switch millions of times a year. The MEMS OXC and the 7221 both document 10⁹ cycles.
- Wavelength range: OXC N×M documents single-mode 1260–1650 nm and multimode 850 ±40 nm options; check that it covers every band you test.
- Return loss and crosstalk: the 7221 documents 45 dB return loss and 55 dB crosstalk.
- Control: RS232 and RJ45 are documented across the range; the 7221 adds Web and programmatic control, which is what test automation software needs.
Built-in power monitoring
The 7221 documents real-time input and output power detection from −50 to +23 dBm on its ports. On a test line this catches a dirty connector or a dead device before a long test is wasted.
What to send us
The number of instruments and devices under test, the wavelength bands, fiber type and connector, the loss and switching time your test plan can accept, and how your software will control the switch. We reply within 24 hours with a configuration.