Month: August 2021

What is a fiber optical attenuator? Why is it used?

Fiber optic attenuators are small passive devices designed to reduce the strength of an optical signal. For those who are unfamiliar, attenuation refers to the rate at which the light or signal loses its strength. Optical attenuators are available in different types, including, fixed, step-wise variable, and continuously variable optical attenuators.

When people learn what fiber optic attenuators means, they typically wonder why anyone would want to introduce attenuation purposely on a fiber optic network. If you are also the one, then keep reading.

Why are fiber optical attenuators useful? Why do you need to accentuate signals?

There are many scenarios in which you need a mechanical variable optical attenuator. For instance, in a multi-wavelength fiber optic system, you need to equalize the strength of optical channel so that every channel has similar power levels. This requires you to reduce the strength of optical signals so that they lower down to match the channels with lower power.

Another example includes the system where received optical power is so much strong that it saturates the receiver. In this case, you will also need an optical attenuator to ensure that the receiver can detect the signal correctly.                                                                                                                                                                    

Hence, you can say that they are proved to be very useful in conditions when the signal arriving at the receiver is too strong and can overpower the receiving equipment.

But, why does a transmitter send too strong signals? This often occurs due to a mismatch between transmitters and receivers. Sometimes, it happens because the media converters are meant to be used for much longer distance than they are currently being used for.

Apart from preventing the receiver from being overwhelmed by too strong signals, optical attenuators are also widely used for stress testing a network link by reducing the signal strength incrementally until the optical link fails. It helps in determining the signal’s existing safety margin.

What are the different types of fiber optical attenuators?

While fiber optical attenuators are typically used in single-mode circuits because of the use of stronger lasers for distance transmission, you can also find multi-mode attenuators.

Male to female attenuators are the most common type of attenuators. They are also known with other names, such as plug-style or buildout style. These attenuators are designed to mount on one end of a fiber optic cable so that the cable can be plugged into the receiving equipment or panel.

There are also female to female attenuators, also called bulkhead attenuators that are often mounted in patch panels or used to connect two optic cables together.

Apart from these, there are variable optical attenuators that are highly useful for testing applications but are more expensive than other types of attenuators. Thus, before you place any order for fiber optical attenuator, you must check which type of attenuator you need and for which application.                                                                                                                                                                 

What Is A Cladding Power Stripper? What Is It Used For?

Nowadays, fiber lasers and amplifiers are being used in a wide range of applications. Their popularity is only increasing as they provide high wall-plug efficiency and superior beam quality even at high power levels. Since their usage is increasing in the commercial sector, the utmost focus is given on their reliability and also of other components required in the system. Thus, to enhance the reliability and robustness of all-fiber lasers and amplifiers at high power, you need to manage unwanted light with extreme efficiency. That’s where a cladding power stripper (CPS) comes into the picture.               

Once you are able to properly manage the unwanted light, you can significantly improve the quality of the system and the output light beam as well. The unwanted light generates across the chain of components forming a system, and each of these components has a specific task to perform. For instance, tapered fused bundle (TFB) couplers are used for combining signal and pump light. They typically have low transmission loss but require protection against the backward traveling light to ensure that they safely function at high power in a real system. Here, you can use cladding power strippers to ensure their safe functioning.

By now, you might have got an idea of what cladding power strippers do. But what are they exactly?

What is a cladding power stripper?

A cladding power stripper is a mode stripping device designed to remove any light that travels in the cladding and helps ensure that the measurements are based only on the effects of the core and not the cladding.

An ideal cladding power stripper features high stripping efficiency, low signal loss, low beam quality degradation, high extinction ratio, high-temperature stability, high power handling capability, and extreme reliability.

It helps you ensure that optical powers are absorbed in a widespread area and that generated heat can be dissipated safely without affecting or damaging the surrounding components.

What are the uses of a cladding power stripper?

A cladding power stripper is widely used in:

  • Fiber amplifiers
  • Fiber laser systems
  • ASE Stripping
  • Life science and Imaging
  • Quantum optics
  • Telecommunication systems
  • Biomedical applications
  • Metrology field

Why do I need to strip light from the cladding of an optical fiber?

The unwanted light in the cladding of the fiber leads to poor beam quality and incorrect measurements. These effects can be more pronounced when you are working with high-power systems. Apart from improving the beam quality, you might also want to prevent the residual light from accompanying the amplified signal or from reaching the signal source. Undesired light in the cladding can also lead to excessive heat which can destroy the coating. Hence, you will need to use cladding power strippers to remove the unwanted light that travels in the cladding.

If you need cladding power strippers in standard or custom specifications or have any queries about cladding power strippers, please feel free to contact us. We offer cladding power strippers in a range of specifications and make sure that we provide you with only quality products.

What are Optical Fused Couplers and Their Types?

Fiber Optic fused Couplers are the key elements in fiber-optic networks for the redistribution of optical signals. Fiber coupler devices are used as small components within various optical modules and systems for long-distance signal transmission, signal amplification, monitoring, and conditioning. They are also widely used in passive optical access networks.

A fiber optic coupler or optical fused coupler is an optical device that is used to distribute the optical signal from one fiber into two or more fibers and vice versa. A basic optical coupler has N input ports ranging from 1 to 64 and M output ports ranging from 1 to 64 for signal distribution. The number of ports on both sides depends on the optical application and network

Manufacturing of Fused Optical Couplers

The manufacturing process of optical fused couplers is known as the Fused Biconical Taper (FBT) process. A fused coupler has two parallel optical fibers that are fused together to bring their core very close to from a Coupling Region. The length of this region determines the coupling ratio from one fiber optic to the other. A light signal is launched into the input port to carefully monitor the output power from each output port during the manufacturing process. After achieving the desired coupling ratio, the manufacturing process is stopped for the particular fused optical coupler.

Types of Fiber Optic Couplers

Fiber optic couplers can be categorized based on various parameters to achieve desired functionality for a specific optical application in a fiber network.

Optical Couplers Classified by Shape

  • Y Coupler

It Resembles the English letter Y, and also known as optical tap coupler. A single input signal is distributed into two output signals using a Y coupler with any coupling ratio from 0.1% to 50% for specific applications. The power distributions ratio is precisely controlled for an optical network.

  • X Coupler (2×2)

It usually resembles the function of an optical signal splitter or combiner. It is used to combines or divides optical power from the input ports to the output ports.

  • Star Coupler

Star coupler combines several input and output ports for desired signal distribution. The number of input and output ports can be in any combination for optical power distribution using start couplers. However, the coupling rations remain equal among all the output ports.

  • Tree Coupler

It is also a multiport coupler, buy only at the output side. It is used to optical power from one input fiber to N numbers of output fibers in an optical fiber network. It is also used reversely to combine multiple optical signals to one output fiber.

Optical Couplers Classified by Wavelength

Optical couplers are usually designed for single wavelength, dual-wavelength or wideband transmissions. You can select optical fiber couplers based on bandwidth, regardless of the type of ports used. As the name suggests, single-window couplers incorporate a single wavelength, dual-wavelength couplers work with two wavelengths at the same time, and wideband couplers are designed for a wider range of wavelengths for optical signal transmission.

At DK Photonics, we sell a wide range of optical fused couplers for a variety of applications in different settings. All the products are tested for high stability and reliability in your fiber network. We also help our clients with customized solutions to meet their specific requirements with high-quality optical passive components. Contact us to discuss your custom needs and requirements.