激光是如何产生的？
发布日期：2023年07月16日 分类：物理学
激光的产生源自于一种物理现象叫做受激发射。激光，全称为“光的激发辐射放大光”，它是一束高度聚焦的电磁辐射，其光波的特点是单色性、相干性和高亮度。
要生成激光，首先需要一个激光介质，比如气体、固体或液体。这个介质中有一些特殊的原子或分子，它们可以被外部能量激发到一个高能级。
接下来，当一个外部能量源（比如一束强光或电能）作用在这些激活的原子或分子上时，它们会从高能级跃迁到低能级。在这个过程中，一些原子或分子会自发地放出一个光子，即辐射出一个光子。这个光子的能量、频率和方向是由原子或分子的能级结构所决定的。
重要的是，放出的光子会引发其他激活态的原子或分子跃迁并放出更多的光子，形成了光的级联放大过程。这种级联放大的过程产生了光的放大效应，使得光子的数量指数级增加，从而形成了一束高亮度的激光。
为了实现光的放大过程，需要在激光介质中创建一个受激发射的反馈回路。这通常通过两个镜子来实现，一个是半透镜，用于允许一部分光线通过，并外部提供能量源。另一个是完全反射镜，它将反射光线回到激光介质中，使光线来来回回多次通过激发原子或分子并放大。这样，光线就能够在介质中来回反射，形成了激光的闭合光路。
最后，当光线经过多次反射和级联放大后，就会达到足够的强度和特定的光的特性，就形成了一束稳定的激光束。这束激光能够具备高度聚焦的特点，因为光线是高度定向、相干且具有单一频率。激光的应用非常广泛，包括光通信、医疗、测距、切割和焊接等。
总结起来，激光是通过激活介质中的原子或分子，并通过级联放大过程产生的一束高亮度、相干性和单色性光线。这个过程需要一个激发源、反射镜和激光介质，通过受激发射的原子或分子间的相互作用，光线经过多次放大与反射后形成了稳定的激光束。
要生成激光，首先需要一个激光介质，比如气体、固体或液体。这个介质中有一些特殊的原子或分子，它们可以被外部能量激发到一个高能级。
接下来，当一个外部能量源（比如一束强光或电能）作用在这些激活的原子或分子上时，它们会从高能级跃迁到低能级。在这个过程中，一些原子或分子会自发地放出一个光子，即辐射出一个光子。这个光子的能量、频率和方向是由原子或分子的能级结构所决定的。
重要的是，放出的光子会引发其他激活态的原子或分子跃迁并放出更多的光子，形成了光的级联放大过程。这种级联放大的过程产生了光的放大效应，使得光子的数量指数级增加，从而形成了一束高亮度的激光。
为了实现光的放大过程，需要在激光介质中创建一个受激发射的反馈回路。这通常通过两个镜子来实现，一个是半透镜，用于允许一部分光线通过，并外部提供能量源。另一个是完全反射镜，它将反射光线回到激光介质中，使光线来来回回多次通过激发原子或分子并放大。这样，光线就能够在介质中来回反射，形成了激光的闭合光路。
最后，当光线经过多次反射和级联放大后，就会达到足够的强度和特定的光的特性，就形成了一束稳定的激光束。这束激光能够具备高度聚焦的特点，因为光线是高度定向、相干且具有单一频率。激光的应用非常广泛，包括光通信、医疗、测距、切割和焊接等。
总结起来，激光是通过激活介质中的原子或分子，并通过级联放大过程产生的一束高亮度、相干性和单色性光线。这个过程需要一个激发源、反射镜和激光介质，通过受激发射的原子或分子间的相互作用，光线经过多次放大与反射后形成了稳定的激光束。
How is a laser produced?
The generation of lasers stems from a physical phenomenon called stimulated emission. Laser, short for "Light Amplification by Stimulated Emission of Radiation," is a highly focused electromagnetic radiation with characteristics of monochromaticity, coherence, and high brightness.
To generate a laser, a laser medium is required, such as gas, solid, or liquid. This medium contains special atoms or molecules that can be excited to a higher energy level by external energy.
Next, when an external energy source (such as a strong light or electrical energy) acts on these activated atoms or molecules, they undergo a transition from a higher energy level to a lower energy level. During this process, some atoms or molecules spontaneously emit a photon, radiating out a photon. The energy, frequency, and direction of this photon are determined by the energy level structure of the atoms or molecules.
Importantly, the emitted photon triggers other excited atoms or molecules to transition and emit more photons, creating a cascade amplification process of light. This cascade amplification process produces the amplification effect of light, exponentially increasing the number of photons, thereby forming a highly bright laser beam.
To achieve the amplification process of light, a feedback loop of stimulated emission needs to be created in the laser medium. This is typically achieved using two mirrors, one being semi-reflective to allow a portion of the light to pass through and provide an external energy source, and the other being fully reflective to reflect the light back into the laser medium, allowing the light to pass through the excited atoms or molecules multiple times and amplify. In this way, the light can reflect back and forth in the medium, forming a closed optical path of the laser.
Finally, after multiple reflections and cascade amplification, the light reaches sufficient intensity and specific characteristics, resulting in a stable laser beam. This laser beam possesses the characteristics of high focus because the light is highly directional, coherent, and has a single frequency. The applications of lasers are wide-ranging, including in optical communications, medical fields, distance measurement, cutting, and welding, among others.
In summary, a laser is a beam of high brightness, coherence, and monochromaticity that is generated by activating atoms or molecules in a medium and amplifying through a cascade process. This process requires an excitation source, mirrors, and a laser medium, where the interaction between the atoms or molecules through stimulated emission results in the formation of a stable laser beam, which undergoes multiple amplification and reflection processes.
To generate a laser, a laser medium is required, such as gas, solid, or liquid. This medium contains special atoms or molecules that can be excited to a higher energy level by external energy.
Next, when an external energy source (such as a strong light or electrical energy) acts on these activated atoms or molecules, they undergo a transition from a higher energy level to a lower energy level. During this process, some atoms or molecules spontaneously emit a photon, radiating out a photon. The energy, frequency, and direction of this photon are determined by the energy level structure of the atoms or molecules.
Importantly, the emitted photon triggers other excited atoms or molecules to transition and emit more photons, creating a cascade amplification process of light. This cascade amplification process produces the amplification effect of light, exponentially increasing the number of photons, thereby forming a highly bright laser beam.
To achieve the amplification process of light, a feedback loop of stimulated emission needs to be created in the laser medium. This is typically achieved using two mirrors, one being semi-reflective to allow a portion of the light to pass through and provide an external energy source, and the other being fully reflective to reflect the light back into the laser medium, allowing the light to pass through the excited atoms or molecules multiple times and amplify. In this way, the light can reflect back and forth in the medium, forming a closed optical path of the laser.
Finally, after multiple reflections and cascade amplification, the light reaches sufficient intensity and specific characteristics, resulting in a stable laser beam. This laser beam possesses the characteristics of high focus because the light is highly directional, coherent, and has a single frequency. The applications of lasers are wide-ranging, including in optical communications, medical fields, distance measurement, cutting, and welding, among others.
In summary, a laser is a beam of high brightness, coherence, and monochromaticity that is generated by activating atoms or molecules in a medium and amplifying through a cascade process. This process requires an excitation source, mirrors, and a laser medium, where the interaction between the atoms or molecules through stimulated emission results in the formation of a stable laser beam, which undergoes multiple amplification and reflection processes.