SHANGHAI FAMOUS TRADE CO.,LTD
SHANGHAI FAMOUS TRADE CO.,LTD
Add to Cart
The ruby laser rod is a cylindrical crystal made from synthetic ruby, a material composed primarily of aluminum oxide (Al₂O₃) doped with approximately 0.05% to 0.5% chromium ions (Cr³⁺). These chromium ions are responsible for the laser activity in the ruby. The ruby rod is typically pink or red in appearance, with the intensity of its color depending on the concentration of chromium ions.
The ruby laser is classified as a solid-state laser, meaning its lasing medium is a solid material, as opposed to gases, liquids, or semiconductors. The ruby used in the laser rod is artificially manufactured to ensure purity and uniformity, making it an ideal medium for producing laser light.
| Property | Specification | Unit/Notes |
| Material Composition | Al₂O₃ doped with 0.05% Cr₂O₃ | Weight percentage |
| Crystal Structure | Trigonal (α-Al₂O₃) | R3c space group |
| Laser Wavelength | 694.3 nm (R₁ line) | Primary emission line |
| 692.9 nm (R₂ line) | Secondary line (low temp) | |
| Physical Dimensions | Diameter: 2-10 mm | Customizable (2mm/4mm shown) |
| Length: 10-200 mm | Standard (10mm/20mm shown) | |
| Optical Properties | Refractive Index: 1.763 694nm | Ordinary ray (nₒ) |
| Absorption Coefficient: 0.4-1.2 cm⁻¹ | Depends on Cr³⁺ concentration | |
| Thermal Properties | Thermal Conductivity: 40 W/(m·K) | 300K |
| Thermal Expansion: 5×10⁻⁶/K (∥c-axis) | Anisotropic | |
| Mechanical Properties | Mohs Hardness: 9 | Second only to diamond |
| Density: 3.98 g/cm³ | ||
| Laser Performance | Fluorescence Lifetime: 3 ms | 300K |
| Emission Cross-Section: 2.5×10⁻²⁰ cm² | For R₁ line | |
| Thermal Lens Coefficient: 3×10⁻⁶ K⁻¹ | Important for high-power operation | |
| Surface Quality | Flatness: λ/10 633nm | Laser-grade polish |
| Surface Roughness: <5 Å RMS | Superpolished finish | |
| Coating Options | AR Coating 694nm: R<0.2% | Typical specification |
| HR Coating 694nm: R>99.8% | For laser cavity mirrors | |
| Damage Threshold | >500 MW/cm² | For 10ns pulses |
The ruby laser rod is optically "pumped" using a high-energy light source, such as a xenon flash lamp or a krypton lamp. The energy from the lamp excites the chromium ions within the ruby crystal, raising their electrons to higher energy states.
After absorbing energy, the excited electrons in the chromium ions cannot remain in their higher energy states indefinitely. They spontaneously drop to a slightly lower energy state, releasing photons in the process. This is called spontaneous emission.
Some of the emitted photons stimulate other excited electrons to release their energy in the form of additional photons. These photons are coherent, meaning they have the same wavelength, phase, and direction. This process of stimulated emission amplifies the light within the ruby rod.
The ruby laser rod is placed between two mirrors—one fully reflective and the other partially reflective. These mirrors form a resonant optical cavity, bouncing photons back and forth through the ruby rod. This repeated passage of light amplifies the coherent light through further stimulated emissions.
A portion of the amplified light escapes through the partially reflective mirror, producing a narrow, intense beam of red laser light with a wavelength of 694.3 nm.
1.Laser Ruby Rod
The cylindrical ruby crystal serves as the lasing medium. Standard dimensions range from a few millimeters to several centimeters in length, with diameters typically between 5 and 15 millimeters.
2.Pump Source
A high-intensity flash lamp (such as a xenon lamp) provides the energy needed to excite the chromium ions in the ruby rod.
3.Optical Cavity
Two mirrors are placed at either end of the ruby rod. One mirror is fully reflective, while the other is partially reflective, allowing the laser beam to escape.
4.Cooling System
Since the pumping process generates significant heat, a cooling system is often incorporated to prevent overheating of the ruby rod and other components.
1.Simplicity: The straightforward design of the ruby laser makes it easy to construct and operate.
2.High Coherence: The emitted laser beam exhibits excellent coherence, making it suitable for precision applications.
3.Durability: The solid-state nature of the ruby rod ensures a long operational lifespan under normal conditions.
1.Holography: The coherent light from ruby lasers is ideal for creating high-quality holograms.
2.Medical Procedures: Ruby lasers have been used for tattoo removal, skin treatments, and other dermatological procedures.
3.Rangefinding: Early laser rangefinders relied on ruby lasers for precise distance measurements.
4.Scientific Research: Ruby lasers have been employed in experiments requiring coherent and monochromatic light sources.
5.Education: As a simple and accessible laser system, ruby lasers are often used in educational demonstrations.
Q:How should ruby laser rods be stored and handled to maintain performance?
A:Storage: In a dry, dark environment (Cr³⁺ is photosensitive).
Cleaning: Use methanol (avoid abrasive cleaners).
Mounting: Minimize mechanical stress (soft indium foil often used for thermal contact).
Pump Source: Match flashlamp spectrum to Cr³⁺ absorption bands (400 nm & 550 nm).
Avoid: Direct UV exposure, fingerprints on polished faces, or thermal cycling beyond 200°C.
Other related products
Cr Al₂O₃ Ruby Rod Sapphire Laser Single Crystal Optical Rod Customized