An illuminator is used to shape a light beam and concentrate it on the end of a fiber optic cable. The light source in an illuminator is a lamp. A halogen lamp is the simplest and most readily available, but it has a limited lifespan (the longest lasting no more than 100-150 hours). A more promising illuminator is a device with a xenon lamp, which, compared to a halogen lamp, has a spectrum of radiation close to natural sunlight. Its service life is longer – at least 500 hours. A xenon lamp illuminator allows for greater illumination of objects with lower energy consumption, due to its higher efficiency. Another key element of the illuminator is the projection optical system, which collects light from the lamp onto the end of the fiber optic cable, the diameter of which typically does not exceed 5 mm, with a specified beam divergence to minimize light loss in the fiber optic cable. The fiber optic cable transmits only those light rays whose angle of incidence does not exceed a certain value, called the maximum aperture angle. The projection system must collect the light from the lamp in such a way that the light beam does not contain rays incident at angles greater than the maximum aperture angle. Typically, the optical system consists of an ellipsoidal mirror, with the radiation source (filament or gas-discharge gap) at one focal point and the end of the fiber optic cable at the other focal point. Other design options for projection optical systems are also possible. In any case, an optical filter that cuts off infrared radiation is mandatory. This prevents possible tissue burns during close contact between the rigid endoscope and internal organs, as well as overheating and fading of the fiber optic cable end. This filter is typically applied as an interference coating to the surface of the mirror reflector. The choice of illuminator depends on the area of ??endoscopic surgery where it will be used. For example, in laparoscopy, a xenon illuminator with the necessary power to illuminate large cavities is indispensable. In pediatric and thoracoscopic surgery, a metal halide illuminator may be sufficient. A powerful xenon illuminator is also necessary when thin endoscopes (2.7 mm, 4 mm) are used to illuminate large cavities, for example, in hysteroscopy or thoracoscopy performed with 5 mm diameter optics. For more detailed information on xenon illuminator prices and specifications, see the Catalog in the Arthroscopy / Arthroscopic Equipment / Light Sources section.