Light source structure: A tube shaped or spherical light bulb made of materials such as glass or quartz. The bubble shell is equipped with electrodes and filled with luminescent gases such as hydrogen, helium, deuterium, xenon, krypton, or metal vapors such as mercury, cadmium, indium, thallium, dysprosium, etc.
Principle of gas discharge: Gas excites electrons and ions under the action of an electric field, becoming a conductor. Ions move towards the cathode and electrons move towards the anode, obtaining energy from the electric field. When they collide with gas atoms or molecules, they excite new electrons and ions, as well as gas atoms, causing the inner layer electrons to transition to higher energy levels. When stimulated electrons return to lower energy levels, they emit photons.
Classification of mercury lamps: low-pressure mercury lamp, high-pressure mercury lamp, ultra-high pressure mercury lamp
The luminous characteristics of mercury lamps: The higher the pressure of mercury, the higher the luminous efficiency of mercury lamps, and the emitted light transitions from a linear spectrum to a band spectrum.
Low pressure mercury lamp - mercury vapor pressure is 0.8 Pa, mainly emitting ultraviolet light at 253.7 nm. Commonly used for wavelength reference, UV sterilization, and fluorescence analysis in spectrometers.
High pressure mercury lamp - The mercury vapor pressure is (1-10) * 10 ^ 5 Pa. The visible region shows a band like spectrum, and the infrared region shows a weak continuous spectrum. Commonly used for UV irradiance standards, fluorescence analysis, UV testing, and large-area illumination.
Spherical ultra-high pressure mercury lamp - mercury vapor pressure is (10-20) MPa. The spectral lines are wide, forming a continuous background, with a blue tint in the visible region and enhanced infrared radiation. Often used as a point light source in optical instruments, fluorescence analysis, and photolithography technology.
xenon lamp
Luminescent material: Xenon.
Spectral characteristics: The spectral distribution is similar to sunlight, with a color temperature of 6000K, high brightness, and a lifespan of several thousand hours.
Classification of Xenon Lamps:
Long arc xenon lamp - electrode spacing of 15-130cm, thin tube shape, working pressure of 105 Pa, used for large-area lighting in docks, squares, stations, etc.
Short arc xenon lamp - with electrode spacing in the order of millimeters and a working pressure of 1-2 MPa, it is an excellent point light source for daylight color, commonly used in film projection, color photography, photographic plate making, simulated sunlight and other occasions.
Pulse xenon lamp - When the pressure inside the tube is below 100 Pa, it is excited by high-voltage electric pulses to generate light pulses, which emit strong light in a very short period of time. Widely used in solid-state laser optical pumps, photographic plate making, high-speed photography, and optical signal sources.