Communications Test and Photonic Control

Polarization Measurement and Analysis

Luna’s advanced polarization measurement systems accurately measure and analyze all polarization related properties of light sources and optical materials.

Luna has a broad range of solutions to measure the instantaneous state of polarization (SOP) and the degree of polarization (DOP), polarization extinction ratio (PER), Wavelength-dependent insertion loss (IL),  Wavelength-dependent polarization-dependent loss (PDL), Wavelength-dependent polarization mode dispersion (PMD), birefringence and many other parameters.

State of polarization and Poincare Sphere Representation

The state of polarization of light is an important parameter of optical signals because it affects how the optical beam behaves when interacting with an optical medium or an optical element. Luna’s in-line polarimeter splits the passing light into four different beams for measuring the Stokes vector components without interrupting the optical signal as shown below:

Stokes vector components

Any SOP can be represented as a point on a sphere with orientation angle Ψ and ellipticity angle χ as the spherical coordinates. This 3D representation of the state of polarization is referred to as Poincare Sphere representation. Luna’s polarimeter can display the real-time changes in polarization on Poincare sphere using PolaView as shown below:  

Poincare Sphere Representation

Polarization Effects in Components and Networks

Various optical components and systems can be sensitive to the state of polarization of the optical signal. For example, a birefringent optical element may attenuate an optical signal differently depending on the incident angle formed with its principal state of polarization (PSP), causing polarization dependent loss (PDL). Moreover, such birefringent optical element may exhibit different refractive indices for different polarizations, causing polarization-mode dispersion (PMD) in optical signals with two orthogonal principal polarization states. 

In fiber-optic communication systems, the presence of PDL and PMD causes data distortion, pulse spreading, degradation in system performance, and ultimately service outage. Therefore, it is becoming increasingly important to precisely measure all polarization related parameters of optical components and systems to control these polarization impairments. Luna offers multiple solutions to measure PDL and PMD with high accuracy using different techniques.

PMD PDL effect on data

Key Measurements for Optical Polarization Measurement

Luna solutions provide the advanced polarization related measurements for complete characterization of optical components and light signals, including: 

  • State of Polarization (SOP)
  • Degree of Polarization (DOP)
  • Insertion loss (IL)
  • Polarization-dependent loss (PDL)
  • Polarization mode dispersion (PMD)
  • Evolution of polarization states
  • Polarization extinction ratio (PER)
  • Birefringence 
  • Jones Matrix elements
  • Muller Matrix elements

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Optical Modules and Components


Optical Modules and Components

Luna offers a complete line of high performance active and passive fiber optic modules and components for a wide range of fiber optic systems, including interferometric systems for fiber optics sensing, fiber optic gyroscope (FOG) and optical coherence tomography (OCT).