Periodically poled self-frequency-doubling green laser fabricated from Nd:Mg:LiNbO_3 single crystal

Abstract

Although a breakthrough in the fabrication of green laser diodes has occurred, the high costs associated with the difficulty of manufacture still present a great obstacle for its practical application. Another approach for producing a green laser, by combining a laser device and a nonlinear crystal, entails the fabrication of complex structures and exhibits unstable performance due to interface contact defects, thus limiting its application. In this work, we report the fabrication by domain engineering of high quality periodically poled LiNbO₃, co-doped with Nd³⁺ and Mg²⁺, which combines a laser medium and a high efficiency second harmonic conversion crystal into a single system that is designed to overcome the above problems. An 80 mW self-frequency doubling green laser was constructed for the first time from a periodically poled Nd:Mg:LiNbO₃ crystal of 16 mm in length. This crystal can be used for developing compact, stable, highly efficient mini-solid-state-lasers, which promise to have many applications in portable laser-based spectroscopy, photo-communications, terahertz wave generation, and laser displays.

Self-frequency-doubling Nd:CTGS laser at 533 nm

“…. All these crystals were reported to show good SFD properties, however, the hexagonal Nd:MgO:LiNbO 3 crystals were found to suffer from detrimental radiation damage induced by the photo-refractive effect [22], while the monoclinic Nd x Y 1Àx Al 3 (BO 3 ) 4 crystals were found to be difficult to obtain high quality crystals due to their poor mechanical properties (cleavage etc.) and long growth period with flux growth method [23].…”

Room temperature 90° phase-matching in zirconium and magnesium co-doped lithium niobate crystals

“…Miniature, compact and high-power all-solid-state blue-green lasers are widely applied in ocean exploration, medical treatment, optical communication and laser display, etc 1 – 4 . As one of the most versatile optical crystals, lithium niobate (LiNbO 3 , LN) plays a key role in the second harmonic generation (SHG) of blue-green light from near-infrared lasers owing to its large nonlinearity and capability of temperature-tuned noncritical phase matching (90° phase-matching) 5 – 8 . Unfortunately, optical damage in LiNbO 3 , also known as photorefractive effect, induced by modest intensities of visible light, sharply decreases the conversion efficiency and hinders its practical usage 9 , 10 .…”

Люминесцентные Свойства Нестехиометрических Кристаллов Ниобата Лития Различного Состава И Генезиса (Обзор)

“…Но стехиометрические кристаллы, выращенные из расплава с 58.6 mol% Li 2 O, характеризуются намного более сильным эффектом фоторефракции [3][4][5][6]. Легирование кристаллов магнием или цинком позволяет снизить эффект фоторефракции и уменьшить величину коэрцитивного поля (до 4.6 и 1.4 kV/mm для Mg и Zn соответственно [7,8]), что важно для создания материалов для преобразования лазерного излучения на периодически поляризованных доменах микронных и субмикронные размеров [9][10][11][12][13][14]. При этом лимитирующим фактором является наличие люминесценции.…”