Application of Er_YAG Side-Pump Module

1. Introduction

The 2940 nm mid-infrared laser is recognized as a golden wavelength in high-end minimally invasive medical treatment, precision special micro-processing, mid-infrared photoelectric detection and cutting-edge scientific research fields. This wavelength perfectly matches the strong absorption peaks of water molecules and hydroxyl groups in organic substances, featuring ultra-short biological tissue penetration depth and extremely low thermal diffusion. It serves as the core light source for high-precision cold processing and minimally invasive diagnosis and treatment with low damage.

As a new-generation core gain unit for solid-state lasers independently developed by Lumispot, the Er_YAG side-pump module adopts a semiconductor lateral pumping architecture. It effectively avoids the defects of short service life and poor stability of traditional xenon lamp pumping structures, as well as the limitations of low power and severe thermal distortion of traditional end-pumping schemes. With high photoelectric conversion efficiency, excellent beam quality, high structural stability and ultra-long service life, this module is widely applicable to the batch manufacturing and miniaturized upgrading of various medical and industrial mid-infrared laser equipment.

2. Core Working Principle and Advantages

Er_YAG (Erbium-doped Yttrium Aluminum Garnet) crystal is a special gain medium for 2940 nm laser output. Its unique energy level transition characteristics enable stable output of 2940 nm mid-infrared laser. Since biological tissues and most organic materials contain a large amount of water and hydroxyl structures, the 2940 nm laser can be efficiently absorbed by material surface molecules. The effective penetration depth is only 2–5 μm, which limits laser energy concentration on the material surface. The thermal conduction range is extremely small, and the thermal damage area is controlled at the micron level, realizing true cold processing and minimally invasive non-destructive operation effects.

Different from the traditional single-sided end-pumping structure, the Lumispot Er_YAG side-pump module adopts an annular multi-array semiconductor laser side-pumping design. Multiple groups of high-power laser chips are uniformly arranged around the Er_YAG crystal rod, achieving 360° uniform coupling pumping from the crystal side wall. This design greatly increases the pumping light receiving area, thoroughly solves the problems of uneven pumping, large radial thermal gradient and serious thermal lens effect in end-pumping structures, optimizes the internal light field distribution of the crystal, and significantly improves laser output stability, uniformity and power upper limit. Meanwhile, the integrated structural design realizes lightweight and miniaturization, with outstanding structural compatibility and replaceability.

3. Main Application Scenarios

3.1 High-end Minimally Invasive Medical Treatment

Benefiting from the characteristics of ultra-low thermal damage, no mechanical vibration and controllable energy, the 2940 nm Er_YAG laser module is widely used in stomatology, medical aesthetics, otolaryngology, orthopedics and other high-precision minimally invasive medical fields. Compared with traditional mechanical surgical instruments and common laser equipment, it has the advantages of less trauma, low bleeding, mild postoperative reaction and fast recovery.

In dental treatment, the module can complete full-process operations such as caries removal, enamel polishing, root canal cleaning and implant bone trimming. Without mechanical vibration and noise, it effectively protects healthy dental and periodontal tissues, reduces anesthesia dosage, improves patient comfort, and lowers surgical risks. In medical aesthetics, the precise and controllable pulsed laser energy is suitable for fractional skin resurfacing, scar repair, stretch mark removal and pigment lesion vaporization. With minimal thermal damage to surrounding skin tissues, thin postoperative scabs and rapid healing, it effectively reduces pigmentation risks and meets the market demand for light medical and rapid recovery aesthetics.

Equipped with optical fiber coupling and endoscopic systems, the module can also be applied to minimally invasive cavity surgery, realizing precise cutting, ablation and trimming of soft and hard tissues. It avoids mechanical extrusion damage, maximally retains healthy tissues, shortens postoperative rehabilitation cycles, and is suitable for various high-standard minimally invasive diagnosis and treatment scenarios.

3.2 Household Minimally Invasive Health Detection

In the field of household health monitoring, the 2940 nm Er_YAG laser module is mainly used in minimally invasive laser blood sampling blood glucose meters, replacing traditional metal puncture needles to achieve painless and minimally invasive blood collection. Combined with test paper enzymatic reaction technology, it realizes high-precision blood glucose detection with accuracy consistent with traditional invasive sampling equipment.

As an optimal water-absorbing laser wavelength, the skin stratum corneum absorption coefficient of 2940 nm is 15 times that of traditional CO₂ laser. The laser energy is instantly absorbed by surface moisture, with an effective action depth controlled at 0.1–0.2 mm, only acting on the epidermal stratum corneum. It instantly vaporizes surface tissues to form uniform micron-level micropores without tearing the skin or damaging subcutaneous capillaries and pain nerves. The blood sampling process only produces a slight thermal sensation, with no obvious pain.

In addition, the laser can realize high-temperature disinfection of sampling pores, eliminating the need for alcohol disinfection and avoiding cross-infection risks. The tiny micropores heal rapidly with almost no scars or bruises left. The detection results are not affected by skin color, age or tissue moisture, featuring stable detection performance, safety and comfort. It is suitable for long-term home blood glucose monitoring of children, the elderly and needle-averse groups.

3.3 Precision Special Micro-Processing

For non-metallic materials containing water and hydroxyl groups, as well as biological materials, the 2940 nm laser has exclusive selective absorption advantages, which cannot be matched by traditional laser sources. It is widely used in high-precision micro-processing scenarios such as bioceramics, artificial bones, dental ceramics restoration, hydrogel biochips and medical polymer films.

In the processing of medical ceramic materials and artificial bone materials, traditional mechanical cutting is prone to chipping, cracking and internal structural damage, while traditional laser processing has large thermal damage and low precision. The Er_YAG side-pump module achieves non-thermal-damage, crack-free and high-precision micro-drilling, surface texturing and micro-structure etching, effectively improving product yield and processing accuracy. For flexible biological materials and polymer films, it can realize precise cutting and patterning without damaging material biological activity and substrate integrity.

At the same time, the module is also applicable to high-end fine processing fields such as jade micro-carving, cultural relic surface non-destructive cleaning and precision coating stripping, fully meeting the mass production and high-precision manufacturing requirements of special materials.

3.4 Infrared Detection, Meteorological Monitoring and Scientific Research

Based on the 2940 nm mid-infrared main wavelength, the Er_YAG laser can also derive the 1645 nm eye-safe infrared band, which features low atmospheric attenuation, strong penetration and no strong radiation damage to human eyes. It is widely used in UAV topographic mapping, long-distance ground laser ranging, space target detection and atmospheric environmental monitoring equipment.

In addition, this side-pump module can be used as a high-stability pump source for OPO parametric oscillation and Raman frequency conversion systems, supporting the expansion of 3–5 μm mid-infrared broad-spectrum laser output. It can be applied to high-precision detection of methane, water vapor, VOCs and other volatile organic gases, and is an important core light source for atmospheric environment monitoring and industrial gas analysis.

In universities and scientific research institutions, the module supports mid-infrared molecular spectroscopy research, laser nonlinear optical experiments, optical component laser damage threshold testing and other cutting-edge scientific research projects. With stable output parameters and high experimental repeatability, it fully meets high-precision scientific research and experimental standards.

4. Lumispot Product Advantages

The Er_YAG side-pump module launched by Lumispot integrates ultra-long service life, high-power stable output, lightweight integration and efficient thermal management. It completely replaces traditional xenon lamp pumping laser modules and solves the pain points of low power limit and serious thermal distortion of end-pumping products. With strong universality and replaceability, it can be widely used in the upgrading and mass production of medical laser equipment, industrial precision processing equipment and scientific research photoelectric systems, and is a high-cost-performance core gain device for mid-infrared laser systems.

5. Product Performance Parameters

6. Typical Test Data

Test Conditions: 500μs Pulse Width, 50Hz Frequency, 22℃ Ambient Temperature, 10% Output Transmittance, 130mm Cavity Length

PIV Curve (Power-Current-Voltage Characteristic Curve)