Abstract
We grew a series of co-doped LiNbO3 crystals with fixed 1.5 mol % ZrO2 and various MgO concentrations (1.0, 3.0, 4.0, 6.0 mol %), and investigated their optical properties and defect structures. By 3.0 mol % MgO co-doping, the optical damage resistance at 532 nm reached 6.5 × 106 W/cm2, while the phase-matching temperature for doubling 1064 nm was only 29.3 °C—close to room temperature—which was conducive to realizing the 90° phase matching at room temperature by slightly modulating the incident angle of the fundamental beam. Notably, we found that the phase-matching temperature increased linearly with the increase of MgO doping, and this linear dependence helped us to grow the high-quality crystal for room temperature 90° phase matching. Moreover, the defect analysis indicated that the linear tuning of phase-matching temperature might be attributed to + neutral pairs in crystals.
Highlights
Lithium niobate (LiNbO3, LN) is a well-known nonlinear optical material for frequency conversion applications, due to its large nonlinearity and capacity for noncritical phase matching in a variety of interactions in the visible and near-infrared [1,2]
MgO-doped LN (MgLN) must be heated to a temperature of ~110 ◦ C to achieve efficient phase matching with the help of a temperature-controlled oven, unavoidably increasing the additional energy losses and the components’ instability [12,13]
We reported that the 1.7 mol % ZrO2 and 5.0 mol % MgO co-doped LN crystal realizes efficient room temperature 90◦ phase matching for doubling 1064 nm, and exhibits high optical damage resistance at 532 nm [14]
Summary
Lithium niobate (LiNbO3 , LN) is a well-known nonlinear optical material for frequency conversion applications, due to its large nonlinearity and capacity for noncritical phase matching in a variety of interactions in the visible and near-infrared [1,2]. Some studies have shown that LN co-doping with some impurities, such as Mg2+ , Zn2+ , In3+ , and Zr4+ , can substantially reduce the optical damage in the visible region above a certain threshold value [4,5,6,7,8] Among these optical-damage-resistant additives, Mg2+ is the most commonly used dopant in LN at this time, and MgO-doped LN (MgLN) heavily promotes the practical applications in high-power frequency conversion [9,10,11]. We reported that the 1.7 mol % ZrO2 and 5.0 mol % MgO co-doped LN crystal realizes efficient room temperature 90◦ phase matching for doubling 1064 nm, and exhibits high optical damage resistance at 532 nm [14]. The UV-visible absorption spectra and the OH− absorption spectra were employed to explore the defective structures of crystals
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
