Article 1: LDD Bar Aging, Beam Comparison, Lifetime Evaluation & Replacement
The structure of the laser LDD bar is shown in the figure below. The shaped beam at the LVD should typically appear as a uniform thin line of approximately 1 × 40 mm. When the LDD bar ages or becomes damaged, common manifestations include: reduced output power, beam deformation, or partial/complete failure to emit light under the same current conditions.
Technical Articles & Tools
1) Laser LDD Bar Structure Diagram
Below are diagrams showing the LDD bar structure and emission units (for understanding fast/slow axis, emission areas, and beam uniformity issues caused by multi-emitter arrays).
2) Beam Comparison (Normal vs Aged/Abnormal)
The shaped beam at the LVD should theoretically be a uniform thin line (approximately 1 × 40mm). The images below show a comparison between "normal beam" and "abnormal beam": abnormalities may manifest as line widening, local collapse, uneven energy distribution, broken lines, or dark segments.
3) Common Aging / Failure Symptoms (Descriptive Supplement)
Under the same current conditions, if any of the following situations occur, it usually indicates LDD bar performance degradation or failure risk:
- Overall power attenuation: Same current, but measured total output power is significantly reduced.
- Beam deformation: Line widening, local energy collapse, blurred edges.
- Partial non-emission (Dead emitters): Dark segments or discontinuous areas appear in the beam.
- Complete non-emission: LDD has failed or is in protection mode.
Additional note: Aging doesn't necessarily immediately manifest as "completely dark"; more often it's "power reduction + distribution deterioration", which directly affects exposure consistency and imaging quality; continued operation at high current may accelerate irreversible damage.
4) Lifetime Evaluation & Test Scripts (TH2 / TH6 / TH7)
We provide laser performance and lifetime test scripts for TH2 / TH6 / TH7, available for free download. After copying the scripts to the corresponding directory, restart Service Tools to use them.
Copy the scripts to this directory: /service/scripts/TH2_TH6_TH7/
Note: If you have authorization (license), you can test and generate charts yourself to evaluate LDD bar lifetime. Authorization license can be obtained from the website.
5) Replacement Process (Summary)
When situations such as "significant power attenuation / light balance failure / partial or complete non-emission" occur, and after excluding contamination and optical path adjustment factors, it is usually necessary to proceed with the "LDD replacement / optics refurbishment / calibration" repair process.
We support: laser LDD replacement / optics refurbishment / board-level repair / calibration. It is recommended to perform free remote diagnosis before sending for repair to confirm the repair path and risks.
6) Related Module Examples (TH Series)
Below are actual photos of modules corresponding to different models (examples).
