Optical cavity

About: Optical cavity is a research topic. Over the lifetime, 17025 publications have been published within this topic receiving 273582 citations. The topic is also known as: optical resonator & resonating cavity.

Multidiameter cavity for reduced mode competition in gyrotron oscillator

Abstract: In a gyro-monotron oscillator a single, "monotron" cavity is used to interact with the electron beam. To handle very high powers without excessive cavity loss, the cavity is excited in a higher order mode such as TE0m1. Other modes can be resonant in the cavity, interfering with the operation when their frequency is near the operating frequency. To increase the mode separation, an upstream section of the cavity is made smaller, to support only a lower-order mode such as TE011. Also, the beam is pre-bunched by this lower order, interference-free mode so has less tendency to interact with spurious modes in the higher order cavity.

Light frequency precise tunable laser

Abstract: The invention relates to a light frequency precise tunable laser. The light frequency precise tunable laser comprises a laser gain medium, an in-cavity collimating lens, an active phase modulator, a tunable acoustooptic filter and an in-cavity totally reflecting mirror which are sequentially arranged in a laser cavity. The light frequency precise tunable laser also comprises an active polarization activizer, a polarization beam splitter, two optical standard tools, a temperature control system, two totally reflecting mirrors, a radio frequency signal source, a laser pumping source, a driving source of the active light phase modulator, a driving source of the active polarization activizer and a laser driving control circuit, and the temperature control system is arranged on the optical standard tools. The light frequency precise tunable laser has a reasonable design, the stable laser output with the light frequency tuning precision smaller than 1GHz and the narrow spectrum bandwidth inthe wide spectrum range is realized through the installation of the temperature control system on the optical standard tools, and the requirement on the narrow band filtering of a tunable optical filter for realizing the light frequency precise tunable laser is greatly reduced, The light frequency precise tunable laser has the characteristics that no mechanical moving components are adopted, the performance is stable and reliable, the cost is low, the dimension is small, the installation and the production are easy, and the like.

Coupling modulation in travelling wave resonator

Abstract: A wideband optical ring modulator is disclosed. A ring resonator containing a synchronous travelling wave electro-optic modulator is disposed external to a laser cavity. The invention provides a compact lightweight optical modulator which combines the power enhancement capabilities of a resonant cavity with the wideband capabilities of a travelling wave coupling modulator. The present invention is especially useful for, although not limited to, ultra-wideband infrared laser communication systems utilizing PCM techniques.

On-line monitoring of the refraction index of air for ultra-precise length measurements in the nano-world

Abstract: In the production of semiconductor microchips, nano-components like MEMS, in the field of optical lithography, an even more precise length measuring devices are necessary for a reliable fabrication. In a lot of cases we can find modern high- resolution laser interferometers. They use a wavelength of the laser beam like a fundamental unit of length. If the interferometers measure distances in atmospheric conditions, the absolute value of the laser wavelength fluctuates in linear form with a refraction index of air. It causes a distortion of the measured values, so that, the repeatability of controlled dimensions can be degraded. To elimination of this influence the on-line monitoring of the value of the refraction index of air is very necessary. On basis of knowledge of the index, the wavelength of the laser beam used in the distance measurement can be corrected to true value. Because the technique of direct measurement of the refraction index are not solved sufficiently now, we put together a new method that uses a special design of an optical resonator working like a laser refractometer. The possible changes of the refraction index of air have the influence to the optical length of the resonator. Principle of monitoring of the length changes of the resonator, down-conversion of the optical frequency changes of a tunable laser into the radio-frequency domain, and experimental verification of the method with any others are key parts of the presented work.

Total-reflection laser resonator

Abstract: Resonant beam is reversely 120 deg totally reflected in the resonant loop made of active material and reversely 90 deg totally reflected in total-reflection prism The partial-reflection prism splits an incident beam into two refracted beams as laser output and reflected beam taking part in resonance Two output laser beams may be combined into one by the combination prism The said structure can raise power and efficiency of lasers