Abstract: The present invention relates to a fiber having a core of crystal fiber doped with chromium and a glass cladding. The fiber has a gain bandwidth of more than 300 nm including 1.3 mm to 1.6 mm in optical communication, and can be used as light source, optical amplifier and tunable laser when being applied for optical fiber communication. The present invention also relates to a method of making the fiber. First, a chromium doped crystal fiber is grown by laser-heated pedestal growth (LHPG). Then, the crystal fiber is cladded with a glass cladding by codrawing laser-heated pedestal growth (CDLHPG). Because it is a high temperature manufacture process, the cladding manufactured by this method is denser than that by evaporation technique, and can endure relative high damage threshold power for the pumping light.

Abstract: A method of fabricating micro crystal fiber lasers and frequency-doubling crystal fibers is disclosed. The micro crystal fiber laser contains gain crystal fibers, frequency-doubling crystal fibers, and a semiconductor laser. The semiconductor laser provides a laser beam. The gain crystal fibers receive the laser beam and generate a base-frequency beam. The frequency-doubling crystal fibers have a polarization alternating period. The frequency-doubling crystal fibers are coupled to the gain crystal fibers to double the frequency of the base-frequency beam and provide a double-frequency beam with the required wavelength. In addition to providing a monochromic crystal fiber laser, the crystal fiber lasers in red, green, and blue light may be combined into an array, providing a color laser. The frequency-doubling crystal fiber can be formed using the LHPG method.

Abstract: The present invention relates to a method for fabricating a crystal fiber having different regions of polarization inversion, comprising the following steps: (a) providing a source material; (b) putting the source material into a fabricating apparatus; and (c) forming the crystal fiber from the source material, and applying an external electric field on the grown crystal fiber during the growth procedure of the crystal fiber so as to induce micro-swing of the crystal fiber for polarization inversion, whereby poling at the time a ferroelectric crystalline body is being formed, whereas the conventional methods are designed for poling a ferroelectric crystalline body after it has been formed.

Abstract: The cavity of the invention has a pumping source, a ring cavity, a planar convex lens, an optical gain medium, and/or a nonlinear medium. The laser cavity is formed by two mirrors with the same curvature. The curving surfaces of the two mirrors are coupled by a manner of face to face, whereby a space is defined as the ring cavity. The planar-convex lens is located between the pump beam and the ring cavity to work together with the two mirrors of the ring cavity to focus the pump beam. The pumping light enters the ring cavity at a desired distance of d mm from the mirror axis. The laser light also enters the ring cavity in a propagating direction nearly parallel to the mirror axis. Due to the two curving surfaces of the two mirrors, the light beam is reflected back and forth to form the 3-D figure-“8” light path. The optical gain medium and the nonlinear medium are located between the two mirrors on the light path.

Abstract: The invention is a frequency stabilized passive Q-switch laser, which has the advantages of small volume, simple structure, no need for high power voltage, etc. It has been a long time that timing jitter in conventional lasers is so large that they can not be applied to fields such as distance measurement. This invention utilizes an optical external modulation method to stabilize the repetition rate of the passive Q-switch, and thus to decrease its timing jitter. At the same time, the repetition rate of the Q-switch laser can be controlled by the same technology to meet various application needs.

Abstract: Two-dimensional electric-filed vector is measured in this invention, wherein two linearly polarized laser beams are focused on two different bottom planes of an electro-optic crystal so that two reflected beams from the bottom planes have two different paths inside the electro-optic crystal and thus have different phase retardation when an electric-field is exerted on the electro-optic crystal by a circuit under test. The electric-filed direction of the circuit can be calculated by using two differential signals which are proportional to the phase retardation of the two reflected beams.