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Wavelength- and OAM- tunable laser with large tunable range is the key source for the application in large capacity optical communications. In this paper, we demonstrate a wavelength- and OAM-tunable vortex laser in a 1.2 W single mode fiber coupled LD pumped Yb:phosphate laser. A z-type cavity has been used to precisely control the laser mode diameter. A thin film polarizer (TFP) is inserted to finely control the intra-cavity loss and tune the wavelength. Corresponding laser fundamental mode to pump beam ratio has been optimized to decrease the pump threshold for high order HG mode running. A pair of cylindrical lenses has been used to convert the HG mode to vortex output. The vortex beam with OAM-tunable range from 1ħ to 14 ħ with wavelength tuning range of ~36.2 nm for LG vortex beam, and ~14.5 nm for LG vortex beam at pump power of only 1.2 W have been realized, which is the largest tuning range of both OAM and wavelength at ~1 W pump power range to the best of our knowledge.
This article was published in the following journal.
Name: Optics express
We present a new technique for measuring the squares of the amplitudes and phases of partial vortex-beams in a complex beam array in real time. The technique is based on measuring the high-order inten...
In terms of the vectorial Rayleigh-Sommerfeld diffraction integral, the analytical expressions of the arbitrary vector vortex Laguerre-Gaussian beams on the higher-order Poincaré sphere diffracted by...
Recently, considerable attention has been focused on orbital angular momentum (OAM) vortex wave, owing to its prospect of increasing communication capacity. Here, a single-layer metasurface is propose...
We explore the long wavelength limit of soliton self-frequency shift in silica-based fibers experimentally and using numerical simulation. We found that the longest wavelength soliton generated by sol...
The generation of ultrashort coherent radiation in the extreme-ultraviolet (EUV) and soft X-ray regimes is of great significance in a broad range of research. In this paper, a promising scheme for gen...
[Development of diagnosis algorism for paroxysmal arrhythmia using ultra-thin resistive membrane: a pilot study] Comparison of blood pressure via tunable crack sensor and invasive pressure...
- Determine the impact and the threshold of long wavelength UVA and visible light on immediate and delayed pigment production of melanocompetent individuals. - The study basicall...
Fundus autofluorescence imaging has become an important diagnostic tool in ophthalmology, guiding diagnosis and assessment of progression of retinal diseases. This study investigates the p...
Treatment of neonatal jaundice is phototherapy with blue light at wavelength about 460 nm and irradiance > 30 uw/cm2/nm. Though, recent in vitro models have suggested that a wavelength of ...
The purpose of this investigation is to study the effectiveness of longer wavelength UVA1 (340-400nm) or shorter wavelength ultraviolet B [UVB] (290-320nm) irradiation in the treatment of ...
A microscopic imaging technique that takes advantage of the process of harmonic generation that occurs when photons interact to generate new photons of a different wavelength. In second harmonic generation, two photons of the same wavelength and frequency, such as from a LASER, interact inside a medium and are converted to a photon of twice the frequency and half of the wavelength of the two incident photons. The light signals captured are used to produce images that are dependent on the unique optical properties of the material.
Tunable liquid lasers with organic compounds (i.e., dye) which have a strong absorption band, used as the active medium. During emission, the dye has to be optically excited by another light source (e.g., another laser or flash lamp). The range of the emission wavelength may be anywhere from the ultraviolet to the near infrared (i.e., from 180 to 1100nm). These lasers are operated in continuous wave and pulsed modes. (UMDNS, 2005)
Scattering of a beam of electromagnetic or acoustic RADIATION, or particles, at small angles by particles or cavities whose dimensions are many times as large as the wavelength of the radiation or the de Broglie wavelength of the scattered particles. Also know as low angle scattering. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed) Small angle scattering (SAS) techniques, small angle neutron (SANS), X-ray (SAXS), and light (SALS, or just LS) scattering, are used to characterize objects on a nanoscale.
Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard X-rays are the higher energy, shorter wavelength X-rays. Soft x-rays or Grenz rays are less energetic and longer in wavelength. The short wavelength end of the X-ray spectrum overlaps the GAMMA RAYS wavelength range. The distinction between gamma rays and X-rays is based on their radiation source.
The science and application of a double-beam transmission interference microscope in which the illuminating light beam is split into two paths. One beam passes through the specimen while the other beam reflects off a reference mirror before joining and interfering with the other. The observed optical path difference between the two beams can be measured and used to discriminate minute differences in thickness and refraction of non-stained transparent specimens, such as living cells in culture.