Nonlinear Optical Crystals: A Complete Survey

Deep ultraviolet (absorption edge 6.2 eV) nonlinear optical (NLO) materials are of current interest owing to their technological applications and materials design challenges. Technologically, the materials are used in laser systems, atto-second pulse generation, semiconductor manufacturing, and photolithography. Designing and synthesizing a deep UV NLO material requires crystallographic non-centrosymmetry, a wide UV transparency range, a large second-harmonic generating coefficient (dij > 0.39 pm/V), moderate birefringence (Δn ∼ 0.07), chemical stability and resistance to laser damage, and ease in the growth of large high-quality single crystals. This review examines the known deep UV NLO materials with respect to their crystal structure, band gap, SHG efficiency, laser damage threshold, and birefringence. Finally, future directions with respect to new deep UV NLO materials are discussed.

Deep Ultraviolet Nonlinear Optical Materials

The development of nonlinear optical (NLO) borate crystals for generation of visible and UV light is reviewed. We first discussed on the basic principles of laser frequency conversion. Then, we examine the trends in research on NLO crystals. The background and present status of NLO borate crystals are summarized. The main considerations are focused on the discussion of crystals like CsLiB6O10 (CLBO), GdxY1−xCa4O(BO3)3 (GdYCOB) and K2Al2B2O7 (KAB). Properties of related materials like β-BaB2O2 (BBO), LiB3O5 (LBO), KBe2BO3F2 (KBBF), Sr2Be2BO7 (SBBO), CsB3O5 (CBO), GdCa4O(BO3)3 (GdCOB) and YCa4O(BO3)3 (YCOB) are included for comparison. We aim to provide a complete view of developing a new NLO borate material for actual laser applications. This review covers various aspects including the search for new materials, the growth of bulk crystals, the characterization of crystal properties as well as the development of new techniques to overcome obstacles in actual laser application, namely, thermal dephasing and laser-induced damage. Finally, perspectives on NLO borate crystals and all-solid-state UV lasers are evaluated.

Recent development of nonlinear optical borate crystals: key materials for generation of visible and UV light

The primary goal of this review is to present a clear chemical perspective of borates in order to stimulate and facilitate the discovery of new borate-based optical materials. These materials, whic...

Borates: A Rich Source for Optical Materials.

Single crystals of Li6CuB4O10 have been synthesized, and its crystal structure has been determined. Li6CuB4O10 crystallizes in the non-centrosymmetric triclinic space group P1 (No. 1). The structur...

Synthesis, crystal structure, and nonlinear optical properties of Li6CuB4O10: a congruently melting compound with isolated [CuB4O10]6- units.

A new lanthanum calcium borate with the composition La2CaB10O19 has been synthesized. Single crystals have been grown from a melt close to the stoichiometric composition. The compound crystallizes in the monoclinic system, space group C2, with a = 11.043(3) A, b = 6.563(2) A, c = 9.129(2) A, α = γ = 90°, β = 91.47°, and two formula units per cell. The crystal structure contains B5O12 double-ring pentaborate groups, which are linked together to form an infinite two-dimensional double layer. The layer runs almost perpendicular to the c axis of the crystal. The La atoms are located in layers, while the Ca atoms are located between two layers. La2CaB10O19 exhibits an optical second-harmonic generation effect about twice as large as that of KDP (KH2PO4).

A New Lanthanum and Calcium Borate La2CaB10O19

We present sum-frequency generation (SFG) characteristics of CsB3O5 crystal (CBO). The effective nonlinear-optical coefficient of CBO in the ultraviolet range is close to its maximum. High-efficiency SFG with a picosecond Nd:YAG laser with output wavelengths of 355 and 266  nm was achieved. Experiments showed that CBO can be used under high power density without damage to the crystal.

Characterization of CsB 3 O 5 crystal for ultraviolet generation

The invention relates to a BaCa4Se7 compound, a BaCa4Se7 nonlinear optical crystal, a preparation method and application. The BaCa4Se7 compound is prepared by adopting a solid-phase reaction, and the BaCa4Se7 nonlinear optical crystal is grown by adopting a high-temperature melt spontaneous crystallization method, a flux growth method or a Bridgman method. In the growth of the BaCa4Se7 nonlinear optical crystal, the crystal is easy to grow and transparent and has no package and the advantages of higher growing speed, low cost, easy obtaining of a crystal in a larger size, and the like. The obtained BaCa4Se7 nonlinear optical crystal has the advantages of wider optical transparency range, larger hardness, good mechanical property, difficult cracking and deliquescence, easy processing and storage, and the like. The BaCa4Se7 nonlinear optical crystal can be used for preparing a nonlinear optical device.

BaCa4Se7 compound, BaCa4Se7 nonlinear optical crystal, preparation method and application

A new series of mixed borates of rare-earth elements and calcium with the composition R2CaB10O19 (where R represents rare-earth element) has been identified in the system R2O3-CaO-B2O3 These isostructural compounds exhibit a powder second harmonic generation (SHG) effect about twice larger than that of KDP (KH2PO4) The crystal structure of La2CaB10O19 (LCB), one member of the RCB family, has been determined by single crystal X-ray diffraction analysis The compound crystallizes in the monoclinic system, space group C2, with a equals 11043(3)angstrom, b equals 6563(2)angstrom, c equals 9129(2)angstrom, (alpha) equals (gamma) equals 90 degrees, (beta) equals 9147 degrees, and two formula units per cell LCB melts congruently with a melting point of 1065 plus or minus 2 degrees Celsius Single crystals of LCB and Nd doped LCB in centimeter size have been grown from the stoichiometric melt The preliminary results on properties of LCB are presented© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering Downloading of the abstract is permitted for personal use only

Yicheng Wu

Papers

A New Lanthanum and Calcium Borate La2CaB10O19

Characterization of CsB 3 O 5 crystal for ultraviolet generation

BaCa4Se7 compound, BaCa4Se7 nonlinear optical crystal, preparation method and application

New class of nonlinear optical crystals R2CaB10O19 (RCB)

A new nonlinear optical material Sr2TiSi2O8