PM Isolator

Understanding PM Optical Isolators: Some Important Applications

Optical reflection is one of the few significant causes of performance degradation in amplifiers and fiber lasers. However, this significant issue can easily be dealt with by using high-quality optical isolators. For those of you who are not familiar with these devices, an optical isolator may be defined as a small device that are designed and created to transmit optical signals in a single direction. Now, this particular device tends to come in two different versions – polarization-insensitive optical isolators and polarization-maintaining optical isolators.

Although both of these versions of optical isolators are effective enough to block any returning light, the insertion loss in a polarization-maintaining optical isolator tends to depend on the input polarization. In this blog, we will shed some light on this particular version of optical isolators.

About Polarization Maintaining (PM) Optical Isolators

Polarization maintaining optical isolators (PM optical isolators) are known to be not just simpler but also very compact when it comes to their design, making them highly suitable for polarization maintaining fiber applications. This type of optical isolator is also highly useful in certain scenarios where an input free space beam of constant polarization tends to pass across the Faraday optics. In both of these applications, the linearly polarized beam that comes from the source is aligned with the transmission axis of the optical isolator.

Even though you can find several types of optical isolators in the market such as fiber-embedded isolators, all-fiber isolators, fiber Faraday rotator isolators, and many others, the core of a commercially available optical isolator tends to consist of a Faraday rotator and a couple of birefringent crystals.

What are the applications of Polarization Maintaining Optical Isolators?

Polarization-maintaining optical isolators have been gaining more and more prominence with each passing day due to the important role they play in modern transmission systems and fiber optic systems. The following are some of the most significant applications of PM optical isolators.

  • One of the main applications of PM optical isolators is that they are useful in applications that are sensitive to unwanted optical reflections and need the presence of polarized light. Since the fact that even a low optical reflection can be enough to increase the laser phase noise, wavelength stability, and intensity noise, the use of PM optical isolators tends to become inevitable in such applications.
  • Polarization maintaining optical isolators are also used in telecommunications and other similar areas such as the likes of biotechnology and sensing such as fiber-optic gyros. Not only this, PM optical isolators can also be seen extensively used in various other applications including fiber amplifiers, fiber sensors, fiber lasers, and so on and so forth.

These were just some of the many applications of polarization-maintaining optical isolators. So, now that you have gained enough knowledge about these devices, you would be able to make the right decision for your particular requirements. However, you must ensure that you deal with a reliable and highly reputed service provider in order to reap all the benefits.