1x2 2x2 Fused PM Fiber Coupler 1020nm 50/50 PM Fiber Splitter For Laser System Optical Instrument

Product Overview

Product Overview: The 1*2 / 2*2 Fused PM Fiber Coupler is a standard polarization-maintaining fiber coupler based on fused biconical taper (FBT) technology, specifically designed for power distribution or combining while maintaining stable polarization. The current specifications are a 1020 nm operating wavelength and a bandwidth of ±15 nm, suitable for laser and precision optics applications in the 1.0 μm band. The standard splitting ratio is 50/50, and it is available in either 1-input 2-output (1*2) or 2-input 2-output (2*2) port configurations to meet the design requirements of different optical topologies. The device uses 980 nm Panda polarization-maintaining fiber as the pigtail, with a standard length of 1.0±0.1 m blue tubular fiber. The package size is a φ3.0*54 mm steel tube structure. It comes standard with an FC/APC connector, with the connector key aligned to the slow axis for easy unification of the polarization reference direction within the system.

Product Applications: At the application level, this Fused PM Fiber Coupler is primarily designed for laser systems and fiber optic precision testing scenarios where high polarization and power distribution accuracy is required. In 1.0 μm band solid-state or fiber laser systems, it can be used to distribute a seed light or amplified light in a 50/50 ratio to two independent channels: one as the main output and the other as a monitoring, feedback, or redundancy channel. In optical measurement and experimental systems, it can be used to build optical paths for interferometry, coherent detection, and phase noise testing, splitting the same light source into two equal-power signals, which are then fed into the tested branch and the reference branch, respectively. In fiber optic sensing and optical power monitoring scenarios, it can act as a front-end beam splitter, equally dividing the main link signal into two paths: one for sensing or operation, and the other for online power monitoring or calibration, thereby improving system observability and security without increasing structural complexity.

Product Features: From a technical perspective, this 1*2 Fused PM Fiber Standard Coupler boasts a comprehensive advantage in terms of low insertion loss, high extinction ratio, high return loss, and high directivity. Taking the 1020 nm specification as an example, insertion loss ≤3.8 dB (50/50 splitting), maintaining good power budget margin even in an FBT structure; polarization extinction ratio ≥20 dB, effectively suppressing undesired polarization components, suitable for polarization-sensitive interferometric and coherent systems; return loss ≥55 dB, directivity ≥55 dB, significantly reducing the impact of end-face reflections and crosstalk on the pre-stage laser, amplifier, and high-sensitivity detector; maximum power handling ≤2 W, meeting the needs of most medium-power 1.0 μm laser applications; operating temperature range -5～+65 ℃, storage temperature -40～+80 ℃, exhibiting good stability and reliability in both laboratory and equipment environments. It's important to note that the specifications specifically state: the version with connectors has an increased insertion loss of approximately 0.3 dB, a reduced return loss of approximately 5 dB, and a reduced extinction ratio of approximately 2 dB. This allows engineers to more accurately estimate actual performance during link budgeting and simulation.

Product Applications (System Integration): From a system integration and engineering implementation perspective, this Fused PM Fiber Coupler is ideally suited as a polarization-maintaining power distribution/combining node within modules or chassis. In the overall design, the 1*2 structure can be directly connected in series at the output of a laser source or active module, splitting one laser beam into two for "main output + monitoring/feedback"; the 2*2 structure can be applied to bidirectional links, ring topologies, or beam combining/splitting multiplexing scenarios, achieving bidirectional signal coupling and separation while maintaining polarization. Because the device is packaged in a small φ3.0*54 mm steel tube, along with a 1 m blue pigtail and FC/APC connector, it is easy to mount and wire in optical circuit boards, compact modules, or 1U/2U chassis. By combining it with isolators, polarization-maintaining circulators, polarization-maintaining amplifiers, and other devices, engineers can quickly build a clear, polarization-controllable, and easy-to-maintain 1020 nm band optical system within limited space.

Product Advantages: Compared to ordinary single-mode fused couplers, the advantages of this 1*2 / 2*2 Fused PM Fiber Coupler are concentrated in three aspects: polarization maintenance capability, parameter controllability, and ease of engineering use. First, it uses dedicated Panda polarization-maintaining fiber, and the default connector key alignment with the slow axis allows the key alignment direction to serve as a unified polarization reference during splicing, cabling, and installation, significantly reducing power fluctuations and phase instability caused by random polarization drift. Second, the device provides clear and quantifiable specifications for insertion loss, extinction ratio, return loss, and power carrying capacity, along with instructions on "parameter correction with connectors," making link design more predictable. Third, through the ordering codes provided in the specifications, including port type (1*2 / 2*2), operating wavelength, splitting ratio, package size, fiber type, fiber length, and connector type, users can quickly select and configure the device according to different project requirements, reducing the number of inventory models and maintenance complexity.

Summary: Overall, the 1*2 / 2*2 Fused PM Fiber Coupler (1020 nm, 50/50) is a core polarization-maintaining passive device for laser systems, fiber optic instruments, power monitoring, and polarization-related experimental platforms. It achieves a good balance between low insertion loss, high extinction ratio, high return loss, high directivity, and medium power carrying capacity, and provides great flexibility for system-level integration through its compact steel tube packaging and standardized connectors. Whether used as a fixed splitter module in mass-produced equipment or as a reconfigurable optical path node in the laboratory, this product helps users build polarization-stable, simple, and easy-to-maintain fiber optic systems in the 1.0 μm band, making it one of the fundamental components that should be given priority when creating high-performance polarization-maintaining solutions.