Homemade high-power lasers are an extremely dangerous and complex task, involving high voltage, strong radiation, flammable materials and potential legal risks. **It is strongly recommended that non-professionals do not try**. The following is a description of the technical principles that are only used for the popularization of knowledge.： --- ###**Core principle** The laser is composed of the following key components： 1. **Gain medium** (such as crystal, gas, semiconductor): determines the wavelength of the laser (such as CO₂, Nd:YAG, ruby). 2. **Pump source** (electrical energy, flash, laser diode): provides energy for the gain medium. 3. **Resonator** (mirror): Coherent light is formed by amplifying photons by reflection. 4. **Cooling system**: It is essential to dissipate heat at high power (water-cooled/air-cooled). --- ###**Technical challenges and risks** 1. **Security risk**： -**Eye/skin damage**: Milliwatt-level lasers can cause blindness, and high-power lasers can burn objects. -**Risk of electric shock**: High-voltage power supplies (thousands of volts) may cause fatal electric shocks. -**Fire risk**: The laser beam ignites flammable substances or the circuit is shorted to cause a fire. -**Legal restrictions**: Most countries have strict controls on high-power lasers. 2. **Technical difficulties**： -**Optical alignment**: Micron-level mirror accuracy requirements (requires professional equipment calibration). -**Thermal management**: The power exceeds 1W and needs to be actively cooled, otherwise the medium will burn down. -**Power supply stability**: High-voltage/high-current power supplies need to be customized, which can easily cause explosions. --- ###**Alternative (for knowledge reference only)** **Low-risk experiment (still need protection)**： 1. **Laser diode module**： - Purchase ready-made 405nm/650nm laser modules (<500mW). -Note: You need to wear laser protective glasses (corresponding to wavelength). 2. **DIY low-power CO激光laser**： -Retrofit old CO激光 laser tubes (such as obsolete products of engraving machines) with a water cooling system. -The output power can reach 10-40W (but professional operation is still required). --- ###**Legal and Ethical Reminder** -In most countries, special permits are required for lasers with an output power of more than **5mW**. -High-power lasers may be classified as weapons (for example, the US FDA requires strict control of Class IV lasers). --- ###**Conclusion** Highly recommended： 1. **Priority is given to the purchase of commercial laser equipment** (such as industrial cutting/engraving machines). 2. **Participate in professional laboratory projects**: Learn laser technology under the guidance of mentors. 3. **Learn basic knowledge**: Get started with textbooks such as "Laser Principles" (Zhou Bingkun). Safety is always the first principle, so don't take risks because of curiosity! 🔴⚠️