Gezhi Photonics PMFWDM series 1550/980 and 1550/1480 models fit fiber optic broadcast architecture, transmitting 1550nm CATV signal at pass port and reflecting 980/1480nm pump light for wavelength combination, enabling triple-play service transmission over single fiber.

Quantified performance matching criteria:

1. Pass port insertion loss ≤0.7~0.8dB, channel ripple ≤0.4dB to stabilize signal fluctuation in long-distance transmission;
2. 23℃ return loss ≥50dB, pass isolation at reflect wavelength ≥30dB to eliminate crosstalk between pump light and video signal;
3. Operating temperature range -5℃~+70℃, suitable for long-term deployment in outdoor optical cabinets and overhead fiber cables.

Optical path rule: Pump light enters common Com port via Ref port, CATV signal outputs from Com to Pass port. Full PM fiber design maintains stable polarization and reduces polarization-dependent loss affecting HD video quality.

For erbium-doped amplification circuits inside dense WDM modules, 1550/980 and 1550/1480 PM filter WDM realize pump coupling and signal demultiplexing.

Quantifiable parameters ensuring stable operation:

• Wavelength thermal stability ≤0.003nm/℃, insertion loss thermal stability ≤0.005dB/℃ to minimize wavelength shift under variable room temperature;
• Pass port extinction ratio ≥20dB, reflect port extinction ratio ≥18dB, full PM pigtails without breaking module polarization circuit;
• Max CW power handling 500mW, compatible with pump power range of standard EDFA modules.

Standard package dimension 5.5*35mm for compact integration inside high-density multi-channel modules, with customizable forward (F) / backward (B) pump path.

FTTH PON networks with optical amplification require co-transmission of 1550nm CATV signal and 980/1480nm pump light. PM filter WDM acts as core passive component for physical wavelength separation.

Key selection indicators:

1. Reflect wavelength isolation ≥30dB to block pump leakage interfering with uplink/downlink data;
2. Test baseline defined without connectors; each additional connector brings only 0.3dB extra loss, convenient for system link budget calculation;
3. Max tensile load ≤5N for pigtail fiber, compliant with wiring and plugging standards to avoid fiber breakage.

1064/980 and 1550/1064 dual-band models serve Yb-doped and Er-doped PM fiber laser systems, reflecting 980nm pump light and transmitting 1064/1550nm signal light unidirectionally, indispensable for MOPA oscillation-amplification optical paths.

Reliability parameters for industrial laser scenarios:

• Storage temperature range -40℃~+85℃, matching laser warehouse storage and high-low temperature aging test procedures;
• High isolation ≥30dB prevents pump back-reflection to protect pump diodes;
• Optional slow-axis-only or dual-axis working modes to match linear polarization laser design.

2000/1550 long-waveband PM filter WDM targets distributed acoustic sensing, fiber optic gyroscopes and coherent precision measurement systems, separating 1550nm reference light and 1950~2050nm detection signal light.

Specialized performance specifications:

1. Pass isolation ≥25dB, reflect isolation ≥12dB for noise suppression in weak mid-infrared signal detection;
2. Continuous PM fiber optical path to preserve polarization purity and guarantee coherent measurement accuracy;
3. Low insertion loss and low thermal drift support long-term stable operation of long-distance pipeline DAS and inertial navigation fiber gyros.

All models support customized configuration to adapt to special optical path designs:

1. Adjustable wavelength combinations, pump transmission directions and polarization working axes;
2. Independent PM fiber selection for Com port and Ref port: PM980, PM1550, Hi1060, SMF-28E and custom fiber types;
3. Bare fiber / 900μm loose tube pigtails, FC/SC APC/UPC connectors and variable fiber lengths on demand;
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The core advantage of PM filter WDM lies in simultaneous wavelength splitting and polarization maintenance, distinguishing it from standard single-mode WDM. Supported by quantifiable low insertion loss, high isolation, wide temperature tolerance and thermal stability parameters, it fully covers five major sectors: CATV PON, WDM optical modules, fiber lasers and mid-infrared precision sensing. Standardized ordering codes enable rapid matching with optical path designs for diverse application scenarios.