Polarization-Maintaining Optical Fiber Devices

Polarization-maintaining optical fiber devices: The technical cornerstone empowering the next generation of optical communications

With the acceleration of the implementation of 5G-A (5G-Advanced), AI computing power clusters, and East Digital and West computing projects, optical communication networks are facing three core challenges: ultra-high bandwidth, ultra-low latency, and ultra-long-distance transmission. In this context, the polarization mode dispersion (PMD) problem of traditional single-mode fibers has become a bottleneck that limits performance, and PM fiber components are becoming a key enabling technology in high-speed coherent communication, quantum communication, silicon-optical integration, and other fields with their unique polarization maintenance capabilities.

01 Science popularization classroom

1. Daily life of ordinary optical fiber: social butterfly

Ordinary single-mode optical fiber is like a "social expert," and the optical signal can be twisted as much as you like in it: horizontal polarization? Vertical polarization? Twist it diagonally into a twist? It doesn't matter; it can be passed on!

Result: When the signal reaches the endpoint, the polarized state is "too drunk to recognize the father," resulting in signals fighting each other during high-speed communication (PMD effect). 

Engineer: "Can your polarization be more stable?!"

Ordinary fiber: "Freedom! It's my attitude!"

2. The birth of polarization-preserving optical fibers: the "obsessive-compulsive patients" of the optical fiber industry

In order to cure this problem of "writhing at will," scientists have added two "physical plug-ins" to optical fibers: 

Move 1: Panda-type protection—symmetrical majesty 

Stuff two "panda eye" stress rods (actually borate glass) on both sides of the core.

Principle: These two "dark circles" desperately pull the optical fiber, causing asymmetric stress inside the fiber core.

Effect: As soon as the light signal comes in, it is "fixed by pressing the head": "Only shake vertically, not horizontally!" 

Light signal: "I want to walk diagonally..."

Panda PM: "No, you don't want to." (Cold) 

Move 2: Bow tie type to protect bias—violent aesthetics

Directly make the fiber core into a "bow tie shape" to physically block the way of other polarization directions.

Principle: It's like stuffing light into a tunnel with only one line and hitting the wall if you dare to turn a corner!

Engineer: "Can this polarization still change?"

Bow tie to protect the part: "Try and die." (Smile)

02 Our solution: full-scenario bias protection product matrix 

In response to the cutting-edge needs of optical communication, we have launched a family of high-reliability polarization protection devices, covering the core technologies of the entire chain of design, manufacturing, and testing: 

1. PM Patch Cord

Features: Panda/bow tie type fiber is optional, with a matting ratio of > 25 dB and a working wavelength covering 780 nm~2 μm.

2. PM Coupler

Breakthrough: Based on the fusion cone technology, 1×2/2×2 spectroscopy is realized, with a polarization-related loss (PDL) of <0.1 dB, supporting harsh environments of -40°C~85°C.

3. PM Isolator

Advantages: Reverse isolation > 40 dB, suitable for narrow linewidth lasers (such as EML), helping to miniaturize CPO (co-packaged optics) packages.

4. PM MEMS Optical Switch

Our polarization protection (PM) MEMS optical switch can support the number of channels 1xN (2≤N≤32); Wavelength: 1310±30 or 1550±30; extinction ratio (PER) dB≥18; switching response time ≤ 20 ms; drive voltage: 5-12V.

5. Polarization Protection Division Multiplexer (PM WDM) 

Polarization-Guaranteed CWDM and Polarization-Maintained DWDM (Available Channels 1/4/8/12/16/18)

03 Technology Highlights: Why Choose Us? 

Military-grade accuracy: Fully automatic axis welding technology, polarization axis alignment error <1°.

Full link test: Passed OTDR, polarization analyzer (such as EXFO PSO-200), and strict quality inspection.

Customized services: Support customers to specify fiber types (such as PM1550 and PM1300) and connectors (LC/APC and MPO).