Customer Return Analysis Report of 10G BIDI 100KM

Customer Return Analysis Report of 10G BIDI 100KM

1.Preliminary test results：

Recently, we received a 10G BIDI 1490/1550NM 100KM product returned by the customer.

Our company conducts normal temperature tests on the modules returned by the customers for confirmation:

The modules with serial numbers SN:HL26C0119003 and SN:HL26C0119004 in the SFP-10G-100BXU series have low emission light. Moreover, the reception of these two modules is not working properly.

2．Analysis procedure：

1.SN:HL26C0119003The actual measured transmission optical power of the module is very low, approximately -22 dBm：

SN:HL26C0119004The actual measured transmission optical power of the module is very low, approximately -18 dBm：

• The low luminance of the above two modules is caused by the movement of the emission devices. It is impossible to improve the power through further debugging. The only solution is to replace the devices. After replacing the devices and conducting another test, the luminance power is as shown in the following figure：

SN:HL26C0119003

SN:HL26C0119004

2. SN:TEL26C0119004When testing the sensitivity of the module on the bit error tester, it was detected that the reception was not working properly. The received optical power signal was approximately -25 dBm, and the received DDM information showed abnormalities:

• After opening the cover, using the voltage setting of the multimeter to measure the reverse high voltage received by the APD (around 30V), the measured voltage was abnormal, and the measured voltage value was 7.3V:

• After removing the APD receiving flexible board, the voltage at the reverse high-voltage output terminal of the main board was measured to be 28.8V again. The measurement was normal：

• According to the test results, it can be concluded that the APD has been damaged. There are two possible reasons for the APD to be damaged: one is electrostatic breakdown; the other is that during use or detection, an excessively high optical power optical signal was input, causing the avalanche diode inside the APD to exceed the limit value and be damaged.
• When detecting or using a product with APD reception, before inputting the optical power signal to the receiving end, each channel's optical power signal should be attenuated to ≤ -7 dBm or below to prevent excessive optical power signals from damaging the APD component.
• After replacing the new Bosa device and conducting micro-adjustments, the sensitivity was tested again. The test results showed normal connectivity.

3.Suggestion：

         A few suggestions during the usage process:

• Pay attention to taking anti-static protection measures
• Keep the fiber optic patch cord connector clean during use

4.Customer suggestions for usage:

Product Operating Instructions

         Optical modules are highly sensitive to electrostatic discharge and improper handling. We recommend that users always follow these precautions during operation:

General Handling

• When the product is not in use, ensure that the dust-proof rubber plug is securely in place.
• If soldering of component pins is necessary, ensure the component is not electrically charged during the process. The soldering iron should have proper grounding, and the soldering time per pin should not exceed 5 seconds, with the soldering temperature kept below 300°C.
• When connecting SFP hot-pluggable products to your system equipment or test platform, insert them carefully and evenly. To remove the product, first pull the pull tab, and then gently pull the product out horizontally.

Fiber Handling
         Optical fibers are extremely fragile. For products with fiber pigtails, the following precautions should be taken:

• When the product is not in use, if you do not have an effective storage method, it is recommended to store it in its original packaging box.
• If the product is not in use, the dust-proof rubber plug of the fiber connector must always be covered.
• Do not place the product in areas where the fiber or pigtail may be subjected to uneven stress or where objects might fall onto it.
• The minimum bending radius of the fiber must not be less than 5 cm.

Cleaning of Fiber End Faces

• Always keep the fiber end faces clean. Contamination of the connected fiber end face can degrade device performance and increase end-face reflection, adversely affecting the system.
• Before testing, clean the end face of the fiber connector. If power fluctuations or blurred eye patterns are observed, clean the end face of the module ferrule with a cotton swab dipped in ethanol. Be extremely careful when wiping the end face to avoid damaging the module.

Electrostatic Discharge (ESD) Hazard
          Optoelectronic devices are highly sensitive to ESD. Adequate precautions must be taken to ensure that operators and test benches remain properly grounded. Even a tiny charge can damage optoelectronic devices, leading to severe product damage or performance degradation.