980/1064nm and 980/1550nm PM WDM Selection
PM WDM selection starts with the pump and signal wavelength pair, port mapping and polarization requirement. Fused and filter constructions must be compared using their own channel-specific loss, isolation, power and fiber specifications. A construction label alone does not establish suitability for an EDFA or fiber laser assembly.
Selection is based on the optical function, the selected product specification and the confirmed fiber interfaces. KernsOptic reviews the available application information before quotation.
Identify wavelength and propagation at each port
A wavelength pair describes which bands are combined or separated, but it does not define the complete optical circuit. Record the pump source, signal source and common fiber path. Indicate whether light travels forward or backward through each interface and whether residual pump light or reflected signal light may reach the component.
Operating bandwidth must cover the source behavior expected at that interface. A nominal wavelength does not establish equal performance across the entire optical spectrum. A request should distinguish the center wavelength from the required pass band and identify which rejection path matters to the system. These definitions make the loss and isolation figures comparable.
Compare filter and fused models as separate configurations
Model 021 is a PM filter WDM with transmission and reflection ranges defined separately for each wavelength combination. Its table also gives different isolation limits for the transmission and reflection ports. Model 022 is a PM fused WDM with its own listed pairs, bandwidth and channel-loss limits. The word PM describes polarization maintenance, not a third construction that excludes either filter or fused devices.
The table below reproduces selected fields from the product specifications. It is a comparison of listed models, not a claim that one construction is universally preferable. Port direction, available fiber interfaces, required rejection and the applicable power condition should determine which model proceeds to configuration review.
Treat power as a model-specific requirement
A standard and a power-rated WDM can share wavelength labels while differing in permitted operating power and packaging. Model 022 lists a 3W CW limit. Model 024 lists 5W, 10W and 20W or specified CW configurations. Those values belong to the selected configuration rather than to every fused WDM or every PM fiber assembly.
Pulse operation requires additional information about the waveform and repetition rate. Connector and splice conditions also affect the completed installation. A power limit should never be inferred from enclosure size or copied from a different wavelength channel. The confirmed specification should identify the conditions used for the proposed build.
Keep polarization and fiber compatibility visible
PM performance depends on the interfaces around the device as well as the internal optical function. Record the PM fiber at each port and the required axis relationship. Extinction ratio must be evaluated under its stated conditions; the value on a component table does not independently establish the polarization performance of an entire amplifier.
When upstream and downstream fibers differ, the request should show both sides. Core and cladding geometry, mode-field compatibility, pigtail length and termination can be reviewed without assuming that every fiber family is interchangeable. The available information can be submitted first; engineering determines which missing details affect the proposed configuration.
Use the correct path loss in the optical budget
The signal budget normally needs the loss of its actual transmission path, while the pump budget uses the pump path. A single insertion-loss number without wavelength and port direction can hide an important difference. Isolation, return loss and directionality are distinct measurements and should retain their product-table names.
For a 980/1550nm EDFA assembly, the dedicated pump WDM guide develops the port and amplifier questions in more detail. The broader WDM and filters category provides model pages and datasheets for comparison. A quotation request should state the intended application, known wavelengths, fiber interfaces and quantity; standard production and testing is assessed at 4–10 weeks after configuration review.
Product specification comparison
The values below belong to the linked product specifications. Options separated by a slash refer to the configurations identified in that model table.
| Model | Parameter | Product specification |
|---|---|---|
| Model 021 | Transmission Wavelength Range | 1020-1080 (1064/980), 1520-1580 (1550/980), 1520-1580 (1550/1064), 1535-1565 (1550/1480), 1950-2050 (2000/1550) nm |
| Model 021 | Max. Optical Power (CW) | 300 / 500 mW |
| Model 022 | Wavelength Pairs | 980/1064, 980/1550, 1064/1550, 793/2000, 1550/2000 nm |
| Model 022 | Max. Optical Power (CW) | 3 W |
| Model 024 | Wavelength Pairs | 980/1064, 980/1550, 1064/1550, 793/2000, 1550/2000 nm |
| Model 024 | Max. Optical Power (CW) | 5, 10, 20 or specified W |
| Model 053 | Pass Wavelength Range | 1020-1080 (0698), 1520-1580 (5598), 1535-1565 (5548) nm |
| Model 053 | Max. Optical Power (CW) | 500 mW |
Frequently asked questions
Is PM WDM an alternative name for filter WDM?
No. PM describes polarization maintenance. PM WDM products can use filter or fused constructions, each with its own specification.
Can Model 022 and Model 024 use the same power limit?
No. Model 022 lists 3W CW, while Model 024 lists 5W, 10W, 20W or specified CW configurations.
Which loss value belongs in an EDFA signal budget?
Use the insertion loss for the actual signal wavelength and propagation path, retaining the conditions and maximum or typical designation in the selected specification.
What should accompany a PM WDM request?
Provide the wavelength pair, intended port mapping, known power conditions and fiber interfaces. Unconfirmed details can be identified during engineering review.