Fiberlink-Connector basic knowledge and product collection

Overview
1. Realize optical fiber connection

It can realize the connection between two optical fibers of the same type/different types, so that the optical signal can be transmitted from one optical fiber to another optical fiber.

2. Pluggable

Optical fiber connectors are also called optical fiber movable connectors. They are live joints that can be plugged and unplugged repeatedly for a certain number of times.

3. High precision

Optical fiber docking requires alignment with um-level coaxial precision, which requires higher precision than docking with traditional electrical connectors.

4. High operating requirements

Compared with electrical connectors, optical fibers have relatively high requirements on the cleanliness and environment of the docking end faces, and the production process is also relatively complex.

What are the product categories of Fiberlink connectors?

1. Communication type
2. Partition-maintaining type
3.Industrial control type
4.J599 aviation plug-in type
5. Outdoor waterproofing type
6. High power type
7. Bundle type

1.Basic principles of connectors
Principle:

The sleeve (sleeve) precisely matches the two ferrules with optical fibers to complete the centering of the two optical fibers; the end faces of the two ferrules are ensured by the retaining springs (springs) on both sides to ensure that their end faces are in close contact.

2. Important indicators of connectors

Important indicators:

◆Insertion loss:

IL= -10log(P1/P0) (dB)

P0----Optical power at the input end

P1----Optical power at the output end

◆Return loss:

RL= -10log(Pr/P0) (dB)

P0----Optical power at the input end

Pr----retroreflected optical power

◆Repeatability:

Changes in insertion loss of optical fiber (cable) movable connectors after multiple plugging and unplugging, △ IL (dB)

◆Interchangeability:

The components of the connector are generally divided into two parts: jumpers and converters. Interchangeability refers to the change in insertion loss △ IL (dB) of any interchange or conditional interchange of these two components.

3. Communication connectors

Optical fiber movable connector

2.5mm ferrule

1.25mm ferrule

Color distinction

APC is generally distinguished by green

Note: Generally, single-mode fiber optic connectors distinguish APC, UPC, and PC end faces, while multi-mode fiber optic connectors do not have APC distinction.

4. Polarization-maintaining connector

Polarization-maintaining optical fiber jumper (pigtail) is a type of optical fiber connector. One or both ends use standard optical fiber movable connectors. Polarization-maintaining fiber is used and the stress axis is accurately aligned to make the fiber jumper (pigtail). We The polarization-maintaining optical fiber jumpers produced by our company use imported polarization-maintaining optical fiber movable connectors. The products have low loss, high extinction ratio and return loss. Fiber end-face AR coating can also be provided according to customer needs for fiber-to-free space coupling optimization.

5. Industrial control connectors

Industrial control connectors generally use quartz multimode optical fiber or plastic multimode optical fiber as the transmission medium. They are used in industrial control signals, audio and video signal transmission and other fields. They have the characteristics of stable transmission and high reliability.

6. High power connectors

Commonly used standard connectors:

D80/FC/SMA905

Common end face treatment methods:

There are also end-face treatment measures such as fiber end caps, coreless fiber splicing, lens collimation, and sapphire lens protection.

High power connector safety hazards:

laser damage
Air-glass interface damage
Insert/connector damage
Damage within optical fiber

①Laser damage

Optical fibers and optical components have theoretical upper limit damage thresholds. Users should comply with actual safety levels to safely operate related components. And consider factors that may reduce power application capabilities and cause damage to fiber components, including but not limited to misalignment during fiber coupling, contamination of the fiber end face, or defects in the fiber itself.

②Air-glass interface damage

Light is incident on this interface when coupling two fibers in free space or using optical connectors to match them. If the intensity of the light is very high, it will reduce the power availability and cause permanent damage to the fiber. For terminal optical fibers that use epoxy resin to fix the connector and optical fiber, the heat generated by high-intensity light will melt the epoxy resin, leaving residue on the surface of the optical fiber in the optical path.

③Insert/connector damage

Fiber optics are typically epoxy bonded into ceramic or stainless steel ferrules. When light is coupled into a fiber through a connector, the light that does not enter the core and propagate in the fiber is scattered to the outer layer of the fiber and then enters the ferrule, where epoxy is used to secure the fiber in place. If the light is strong enough, it can melt the epoxy resin, causing it to vaporize and leave a residue on the joint surface. In this way, local absorption points appear on the fiber end face, resulting in reduced coupling efficiency, increased scattering, and further damage.

④Damage within the optical fiber

If the angle of light propagating in the fiber core and incident on the core-cladding interface is greater than the critical angle, it will not be fully reflected. The light will exit the fiber in a certain area, and bending loss will occur. The light emitted from the fiber generally has a high power density and will burn out the fiber coating and surrounding loose tube. The second damage mechanism in optical fibers is called photodarkening or negative induction, which generally occurs in ultraviolet or short-wavelength visible light, especially in fibers with germanium-doped cores. Fibers operating at these wavelengths will experience increased attenuation as exposure time increases. The causes of photodarkening are largely unknown, but there are a number of measures that can be taken to mitigate them. For example, studies have found that fibers with very low hydroxyl ion (OH) content are resistant to photodarkening, and that other dopants, such as fluorine, can also reduce photodarkening.

Precautions：

· Optical fiber end face coating;

· Coupling optical lenses/end caps to reduce power density;

· Fiber end face cleaning inspection;

· Standardize operations.

7. Outdoor waterproof connector

ODC is a metal connector, generally made of copper alloy or aluminum alloy. It is easy to process and has low cost. It is suitable for mobile base stations, outdoor equipment and other scenarios. It has a waterproof rating of IP67. Protective connectors such as PDLC, ODVA, and FULLAXS are all made of protective plastic shells based on standard communication connectors. They have reached IP67 protection. Their costs are low and they are widely used in the field of mobile communications.

8. Bundle connectors/components

Generally non-standard customized products

Transmission medium:

①Quartz optical fiber:

·Long transmission distance;

· Low loss (high transmittance);

· The acceptable angle is small,

Generally NA0.22-0.64;

· The monofilament diameter is larger,

Generally >50μm;

· higher cost

②Glass optical fiber;

·Short transmission distance, 5-6m;

· High loss (50%-80% throughput);

· Large acceptance angle

NA up to 0.8

· The monofilament diameter is thin

Generally 30-50μm;

· higher cost

Terminal form:

①Arrangement rules

It can be arranged according to the requirements of points and surfaces; the difficulty is high; the end surface can be designed to withstand high temperatures of 600-800°C; the number of integrated cores is small; the cost is high.

②Random arrangement

The cross-sectional area of light can be customized; the difficulty is relatively easy; the material channels are easily limited, and the NA can be up to 0.8; the diameter of the single filament is thin, generally 30-50μm; and the cost is low.

9. J599 aviation plug-in connector

Standard: Comply with GJB599B (MIL-C-38999H) specification;

Appearance: circular connector;

Connection method: three-head thread connection, bayonet connection;

Installation method: flange installation, nut installation method;

Several common series

J599 III connector

The J599 III series circular optical fiber connector adopts a three-head thread quick locking mechanism and five-button circumferential positioning. It is waterproof, dustproof, and corrosion-resistant.

★ Passivated stainless steel shell, with electromagnetic shielding function, salt spray resistance up to 1000h;

★Using ceramic optical contacts for precise docking, low loss, and reliable connectors;

★The contact density is high, which can meet the 2-26 core multi-channel optical fiber transmission requirements;

J599 A8 connector

The J599 A8 series connector adopts an all-metal structure, and the opening mounting plate adopts a detachable structure, which facilitates on-site installation, replacement and maintenance, and improves product reliability.

★ The interface complies with ARINC801 standard;

★Three-head thread fast locking, five-key circular positioning, and anti-misinsertion function;

★Stainless steel shell, corrosion-resistant, all-metal structure, meeting radiation resistance requirements;

★EB (expanded beam) ferrule can be provided, and the service life can be increased to >3000 times.

J599 A6 connector

The J599 A6 series connector is an all-metal structure, and the opening mounting plate adopts a detachable structure, which facilitates on-site installation, replacement and maintenance, and improves product reliability.

★ Passivated stainless steel shell, corrosion-resistant;

★Interface complies with ARINC801 standard;

★Bayonet connection, five-button positioning;

★EB (expanded beam) ferrule can be provided, and the service life can be increased to >3000 times;

J599 MPO connector

The J599 MPO series connector is a high-density, high-speed connector product that uses standard MT ferrules as optical contacts and can provide 12-48 core optical transmission channels.

★ Passivated stainless steel shell, corrosion-resistant;

★Using MPO standard connector, small size and high transmission density;

★Using double guide pin structure, high positioning accuracy and low transmission loss;

★Three-head thread fast locking, five-key circular positioning, and anti-misinsertion function;

J599 MT connector(GYM)

J599 MT series connector is a high-density high-speed connector product that uses standard MT ferrules as optical contacts and can provide 12-96 core optical transmission channels.

★ Passivated stainless steel shell, corrosion-resistant;

★Using MT ferrule, small size and high transmission density;

★Using double guide pin structure, high positioning accuracy and low transmission loss;

★Three-head thread fast locking, five-key circular positioning, and anti-misinsertion function;

J599 optical and electrical hybrid connector

J599 optical and electrical hybrid series connectors adopt an all-metal structure with mixed internal optical and electrical contacts to increase the variety of transmission methods.

★ The interface complies with GJB599B standard;

★Three-head thread fast locking, five-key circular positioning, and anti-misinsertion function;

★Stainless steel shell, corrosion-resistant, all-metal structure, meeting radiation resistance requirements;

Main features of each series

Main features of J599 III series/photoelectric hybrid series

· Shell number 9-25, diameter size: 21.8mm-48.00mm;

·Supports 1-60 channels of pure light and photoelectric mixed installation;

·Loss: single mode <1.0dB, multimode 0.6dB;

·Rated single-core current of electrical pins: 5-20A optional;

·Material: W aluminum alloy cadmium plated (military green), F aluminum alloy chemical nickel, K stainless steel passivation;

·Three-head thread structure, five-key circular positioning, supports changeable key positions.

Point 1: Shell number

Plug：

Point 2: Convertible location

Point 3: III Series Contacts

Optical contacts (common 20#, 16#, 12#)

Electrical contacts

Contact resistance and rated current of electrical contacts：

Main features of J599 A8/A6 series

· A6/A8 difference: A8 three-head threaded connector, A6 bayonet connection;

· Shell number: 11-25, diameter size 25mm-48mm:

· Support 1-32 channels of pure light;

· Loss: single mode <0.6dB, multimode 0.4dB;

· End face type supports UPC and APC optional;

· Material: W aluminum alloy cadmium plated (military green), F aluminum alloy chemical nickel, K stainless steel passivation;

· Three-head thread structure, five-key circular positioning, and support for changeable key positions.

· Optional ferrule with expanded beam lens (EB ferrule), the number of insertion and removal is >3000 times.

· The plug has a detachable structure, making it easy to clean, maintain and replace.

Point 4: UPC\APC

PC: pure plane;

UPC: A flat surface with a certain arc;

APC: Arc plane with an 8-degree angle.

Point 5: Expanded beam ferrule (EB)

·Expand fiber core area: 9or62.5 to 1mm; reduce the impact of dirt;

·Non-physical contact increases the number of contacts and extends the service life;

·Disadvantages: Large loss, generally 1.0-1.5dB.

Point 6: Detachable structure

The printed circuit board part of the plug is removable, and the user can clean the end face of the ferrule by himself.

Main features of J599 MT (GYM)/MPO series

· GYM uses MT high-density ferrules, and a single ferrule can achieve 12-48 channels of optical signal transmission;

Shell number: 9, 11, 13, 21, diameter size 21.8mm-41.7mm

· Supports 1-4 MT ferrules, with a maximum channel number of 192;

· Loss: <0.7dB

· End face type supports UPC and APC optional;

· Material: W aluminum alloy cadmium plated (military green), F aluminum alloy chemical nickel, K stainless steel passivation;

· Three-head thread structure, five-key circular positioning, and support for changeable key positions.

· The MPO series has a built-in MPO connector (excluding MPO shell), which supports up to 48 cores. Compared with the MT series, the positioning accuracy is higher and the loss is lower.

Point 7: MT ferrule

A single MT ferrule supports up to 48 channels in multi-mode and 36 channels in single-mode.

Common definitions of connectors

For specific information, please check the corresponding information in the specification book. Each manufacturer will have differences.

Common component structures of connectors