Accurate polarization,efficient transmission:Unveiling the black technology of PM fiber couplers

2024-07-20 17:44:13

A polarization-maintaining fiber coupler is an optical device primarily used for coupling, splitting, and multiplexing linearly polarized light. It enables the stable transmission of two orthogonal linearly polarized lights while preserving their respective polarization states. This characteristic makes it a crucial component in military interferometric sensors, coherent optical communications, fiber-optic gyroscopes, fiber hydrophones, and other systems.

Working Principle of Polarization-Maintaining Fiber Coupler

The working principle of a polarization-maintaining fiber coupler can be simplified into two main steps: capturing and coupling.

Capturing Stage:

In this stage, one end of the fiber is placed in a small tapered hole. The tapered end gradually decreases in angle until its size matches that of the core of the coupled fiber.

By progressively adjusting the angle of the tapered end, light refracts out of it and matches with the light inside the coupled fiber. Maintaining the direction and angle of the tapered end consistent with the fiber core is crucial for efficient light capture.

Coupling Stage:

In this stage, the light from two polarization-maintaining fiber cores is cross-coupled. By finely adjusting the position and angle of the tapered end, coupling occurs as the two light beams intersect.

Once coupled, the light propagates randomly along the fiber. Since both light beams have the same collimation properties and undergo the same refraction and crossing principles, they maintain their coupling state during continued transmission, minimizing signal loss and distortion.

Characteristics of Polarization-Maintaining Fiber Coupler

Polarization Maintenance: Capable of stable transmission and preservation of the polarization states of two orthogonal linearly polarized lights.

High Precision: Requires precise fiber drawing techniques and fine-tuning control during manufacturing to ensure accurate coupling and efficiency.

Low Loss: Effective coupling mechanisms reduce light signal loss during transmission.

High Stability: Maintains stable performance under various environmental conditions, unaffected by external factors.

Applications of Polarization-Maintaining Fiber Coupler

Polarization-maintaining fiber couplers find widespread applications in several fields:

Optical Communications: In fiber-optic communication systems, they preserve the polarization state of optical signals, enhancing transmission quality and stability.

Optical Sensing: Essential in optical sensing systems like fiber-optic gyroscopes and fiber hydrophones for achieving high-precision measurements.

Medical Imaging: Used in medical imaging devices, such as optical coherence tomography (OCT), to ensure accuracy and stability of imaging results.

Scientific Research: Supports high-precision experiments and measurements in optics, physics, materials science, and other research fields.

In summary, polarization-maintaining fiber couplers, with their unique polarization maintenance capabilities, high precision, low loss, and high stability, have found widespread applications and development across multiple domains.

Shenzhen optics forest Co.,Ltd have PM Filter Coupler and Fused PM Fiber Coupler

1x2(2x2) Fused PM Fiber Standard Coupler (Mixer) as follows:

Specifications
Parameter		Unit	P	A	P	A
Port Configuration			1X2or 2X2
Center Wavelength		nm	780, 830, 980, 1064		1310, 1480, 1550, 2000
Bandwidth		nm	±20
Excess Loss	Typ.	dB	0.6	0.8	0.2	0.3
Excess Loss	Max.	dB	0.8	1.0	0.4	0.6
Polarization Extinction Ratio	Min.	dB	18	15	20	17
Operating power	Max.	W	2
Operating Temperature		°C	-40 to +85
Storage Temperature		°C	-50 to +85

Splitting Ratio & Its Tolerance
Splitting Ratio	Maximum Splitting Ratio Tolerance (%)
Splitting Ratio	P	A Grade
99/1	±0.5	±0.6
98/2	±0.8	±1.0
95/5	±1.5	±1.7
90/10	±2.2	±2.4
80/20	±2.5	±3.0
70/30	±3.0	±3.7
60/40	±4.0	±4.8
50/50	±5.0	±6.0

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Accurate polarization,efficient transmission:Unveiling the black technology of PM fiber couplers

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