A university optoelectronics laboratory was developing a distributed fiber-optic sensing system and needed to monitor and analyze the state of polarization (SOP) of the sensing signal in real time. The researchers wanted to evaluate how polarization noise affected sensing accuracy.

Their existing setup relied on a general-purpose oscilloscope and photodetector for indirect measurements. This approach could not accurately obtain polarization-state parameters and lacked the sampling performance needed to capture transient polarization fluctuations.

To address these limitations, Joinwit supplied a polarization monitoring solution built around the JW8611 In-Line Polarimeter. The instrument acquires all four Stokes parameters in real time, while PC software plots the polarization trajectory on a Poincaré sphere, allowing researchers to observe and analyze polarization evolution in the fiber more intuitively.

The system was also paired with the JW8612 PM Fiber Thermal Cycling Heater for precise polarization extinction ratio (PER) measurements of narrow-linewidth light sources. This solution has supported multiple fiber-sensing and polarization-related research projects at the laboratory and received positive feedback from the research team.

Our client is an MPO/MTP cable manufacturer that faces several challenges in production testing for multi-fiber optical components. Conventional return-loss testing methods requiring fiber winding were unsuitable for multi-fiber assemblies, affecting measurement accuracy. Testing a 24-fiber MPO patch cord one channel at a time also took considerable time, while using several separate instruments complicated the workflow and made test data harder to manage consistently.

Joinwit addressed these issues with an integrated MPO testing solution centered on the JW18001 MPO IL/RL Test Platform. The platform combines automated insertion loss (IL), return loss (RL), and polarity testing for multi-fiber assemblies in one system.

Its non-winding return-loss measurement method eliminates the need to wind multi-fiber cables during RL testing. Each channel can be tested in 0.6 seconds, and a 24-fiber dual-wavelength test can be completed within one minute. The software also supports polarity learning, adaptive fiber-sequence configuration, and data storage in multiple formats.

Following implementation, the manufacturer significantly improved production-line testing efficiency and established traceable test-data management throughout the testing process. The solution has also been adopted for volume use by multiple leading manufacturers in the sector.

A national telecommunications operator needed to test fiber loss and locate faults during the construction and acceptance of metropolitan-area and secondary backbone fiber links. Individual links could exceed 120 km, while the dynamic range of the operator’s conventional OTDR equipment was insufficient to test the entire link in a single measurement. However, segment-by-segment testing reduced efficiency and made result consolidation more difficult.

Joinwit supplied a backbone-network testing solution based on the JW3703 Optical Time-Domain Reflectometer (OTDR). With a maximum dynamic range of 45 dB, the JW3703 supports accurate testing over distances of more than 180 km, enabling loss measurements and event analysis across an entire backbone link in a single test.

Up to 256k sampling points and a sampling resolution of 2.5 cm support more precise fault location. Measurement results, OTDR traces, event lists, and maps can be displayed on the same screen, helping field technicians assess link conditions more efficiently. After deployment, backbone-network acceptance testing became significantly more efficient, with the test time for an individual link reduced by more than 60%.