"Polarization-Maintaining PM-ESF-7/125" refers to a panda-type polarization-maintaining erbium-doped fiber.
Structure and Principle
Polarization-Maintaining Principle: PM-ESF-7/125 belongs to panda-type polarization-maintaining fibers, which have two symmetrical stress regions. By introducing stress into the fiber, the two orthogonal polarization modes in the fiber have different propagation constants, thus achieving the function of polarization maintenance, reducing polarization mode dispersion, and ensuring that the polarization state of the light wave remains basically unchanged during transmission.
Doping Characteristics: This fiber is an erbium-doped fiber with a high erbium ion doping concentration. The peak absorption at 1530nm can reach 55dB/m, which can effectively realize functions such as optical signal amplification.
Performance Parameters Optical Parameters
Mode: Single-mode fiber, ensuring that optical signals are transmitted in a single mode, reducing mode dispersion and improving signal quality.
Birefringence: The birefringence value is ≥3.5×10⁻⁴. High birefringence enables the fiber to better maintain the polarization state of light.
Polarization Crosstalk: At the wavelength of 1300nm, the polarization crosstalk is < -35dB/4m, indicating that the fiber has a high isolation degree between different polarization modes, reducing the impact of crosstalk on the signal.
Second-Order Mode Cut-off Wavelength:
It is 1460±60nm, ensuring that the fiber can maintain single-mode transmission within the working wavelength range.
Dimension Parameters
Core Diameter: 7.4 microns.
A smaller core diameter helps to restrict light transmission in the core and improve the interaction efficiency between light and doped ions in the core.
First Cladding Diameter: 125 microns, providing optical confinement for the core to enable efficient light transmission in the core.
Coating Diameter: 245 microns. The coating can protect the fiber from the external environment and improve the mechanical strength and service life of the fiber.
Other Parameters
Working Wavelength Range: 1530-1625nm.
Within this wavelength range, the fiber can achieve good optical performance, suitable for various applications such as optical communication and optical sensing.
Numerical Aperture: 0.15. The numerical aperture determines the ability of the fiber to collect and transmit light, and this value allows the fiber to be well coupled with other optical devices.
Proof Test Level: 100kpsi (0.7GPa), indicating that the fiber has high mechanical strength and can withstand certain tensile and compressive forces.
Characteristics
High Conversion Efficiency: Due to high erbium ion doping and unique technical design, it has high pump conversion efficiency, which can effectively convert pump light into signal light and improve the performance of optical amplifiers and other devices.
Excellent Polarization Characteristics:
As a polarization-maintaining fiber, it can well maintain the polarization state of light, providing stable polarization output for applications requiring polarized light.
Good Beam Quality: It can achieve laser output with narrow linewidth and high beam quality, suitable for application scenarios with high requirements for beam quality, such as laser processing and laser ranging.
High Reliability:
Adopting NuCoat FA™ coating technology, it has good anti-environmental interference ability,
can work stably for a long time in extreme environments, and improves the reliability and service life of the fiber.
