The Compass for Precise Optical Conversion: Decoding the Crystal Product Marking System
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Publish time:
2026-04-17
The Compass for Precise Optical Conversion: Decoding the Crystal Product Marking System
When you receive one of our carefully packaged crystal products and start setting up your experiment, have you ever wondered how to interpret the dots, arrows, chamfers, and other markings on the crystal surfaces? Rest assured, this guide will provide a detailed introduction to the scientific principles and practical significance behind our crystal product marking system, ensuring optimal results for each experiment.
I. Why Crystal Marking is Critical to Your Experiment
Our nonlinear optical crystals, such as LBO and BBO, function like precision wavelength converters, efficiently transforming laser light from one wavelength to another. To achieve this high-efficiency conversion, both phase matching and polarization matching conditions must be satisfied.
Phase Matching：The laser wave vector direction and the optical axis direction must satisfy a specific angle.
Polarization Matching：The laser must pass through the crystal with a specific polarization direction.
These "precise requirements" are not inherently visible. Our professional marking system is designed to translate these invisible constraints into clear, physical guides on the crystal itself. Operating a crystal without these reference marks can lead to a significant drop in conversion efficiency or even a complete failure to generate the desired output wavelength. With our systematic markings, complex initial measurements are unnecessary. Simply aligning your setup according to the provided guides ensures accurate, repeatable alignment every time, guaranteeing stable and reliable experimental results.
II. Our Crystal Marking System
Our crystal marking system consists of three key components: the marking style, the marked surface, and marking direction surface.
- Marking Style
Let’s start with the basic classification: according to whether the crystal length along the beam path is greater than or equal to 2.5 mm, the markings are divided into thick-crystal markings and thin-crystal markings.
Thick Crystals:clear markings such as dot + arrow, chamfering, or trihedral chamfering
Thin Crystals:refined markings such as blackened surface, greater-than symbol, dot marking, or chamfering
Custom Requirements:personalized markings such as numbers, letters, etc., can be provided according to customer specifications
- Marked Surface
Through precise orientation technology, the internal crystal axes (X, Y, Z axes) are accurately determined, and markings are made at the optimal position. The marking surface is usually chosen to be a side face, which is the face corresponding to one optical axis being perpendicular to the other two axes.
- Marking Direction Surface
The marking direction surface clearly indicates the path of light through the crystal. Taking the common dot + arrow marking as an example, the arrow precisely indicates the transmission face through which the laser should enter perpendicularly, ensuring that the beam passes through the crystal in the direction indicated by the arrow and achieves the best conversion performance.
III. Detailed Explanation of Our Crystal Marking System and Application Example
Our standard crystal markings are as follows:
- Application Example: LBO Crystal Frequency Doubling
Taking an LBO crystal used to frequency-double 1064 nm into 532 nm green light as an example (type I phase-matching angle: θ = 90°), the crystal is marked with a dot + arrow on the XOY plane, as shown below:
The dot indicates the direction of the optical axis Z, and the arrow indicates the direction from the S1 face to the S2 face. When the customer receives the crystal, the polarization direction of the fundamental wave (1064 nm) should be perpendicular to the marked face, and the fundamental wave should be incident normally on the S1 face. By making slight rotations around the tuning axis Z, the optimal angle matching can be obtained, achieving maximum conversion efficiency.
The figure below shows the polarization directions of the fundamental wave and the second-harmonic wave.
IV. Professional Assurance:
We understand how important marking clarity is to experimental success. If the markings are worn or if you have any questions about the directional markings, we provide comprehensive professional support:
Professional technical support: Our technical team can provide remote guidance and answer any questions you may have.
Precision re-verification service: If necessary, you may return the crystal to us, and we will recalibrate the axis and restore the markings using the original drawings and process records under professional equipment.
If you have any questions about crystal markings, please feel free to contact us — we are always here to support the success of your experiments!
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