Selection / comparison
PM vs SM Optical Isolator
Understand when a polarization-maintaining isolator is required and when a standard SM version is sufficient.
Use this page when the application is known but the component specification still needs to be narrowed before RFQ.
Selection logic
PM isolator
Use when the system must preserve a defined polarization state and extinction ratio is part of the specification.
SM isolator
Use when polarization orientation does not need to be maintained through the component.
What to send
Wavelength, power, fiber type, connector, required isolation/IL and package constraints.
Quick comparison
| Requirement | Choose |
|---|---|
| Preserve polarization / ER specified | PM isolator |
| Polarization not critical | SM isolator |
| Unsure | Send application + fiber + power for engineering review |
Have a target specification already?
Use Component Finder or send the known parameters directly to engineering review.