Handbook of optics

Nonlinear Optical Crystals: A Complete Survey

We report measurements of all the material constants necessary to fully characterize barium borate as a nonlinear optical material. All data was taken on crystals supplied by Professor Chuangtien Chen, Fuzhou, People’s Republic of China. We have determined the crystal structure, the optical absorption, the refractive indices from the UV to the near IR, the thermo‐optic coefficients, the nonlinear optical or coefficients, the resistance to laser damage, the elastic constants, the thermal expansion, thermal conductivity and dielectric constants, and the fracture toughness. This data is used to evaluate barium borate for a variety of applications. We find that, in general, barium borate has a low acceptance angle, and that despite its higher optical nonlinearity, it is therefore not significantly more efficient than other commonly available materials, except in the UV below 250 nm. On the other hand, it has a high damage threshold, it is physically robust, it has good UV and IR transparency, and it has excellent average power capability. It permits deep UV generation, and has great potential for generating tunable visible and IR light as an optical parametric amplifier.

Optical, mechanical, and thermal properties of barium borate

LASER INSULATING CRYSTALS AND THEIR STIMULATED EMISSION Development of Crystal-Laser Physics (Short Historical Remarks) Fluorine- and Oxygen-Containing Laser Crystalline Hosts and Their Activator Ions Other Laser Crystals Stimulated-Emission Channels of Activated Insulating Laser Crystals Stimulated Emission 4fN-4fN and 4fN-15d1-4fN Channels of Ln3+ Ions Laser Channels of Ln2+ and U3+ Ions Laser Channels of Cr3+, Cr4+, Ti3+, and Mn5+ Ions Laser Channels of TM2+ Activators Crystalline Laser Hosts for Obtaining Generation of Ln3+ Activators at New Wavelengths References ENERGY LEVELS AND OPTICAL-TRANSITION INTENSITIES OF GENERATING ACTIVATORS IN INSULATING LASER CRYSTALS Stark-Level Structure of Lasing Activator Ions Basic Concepts of Modern Crystal-Field Theory Stark-Level Energies of Generating Ions in Laser Insulating Crystals (Experimental Data) References Intensity of Radiative Transitions of Ln3+ Activators in Insulating Laser Crystals Electric Dipole Transitions Judd-Ofelt Intensity Parameters Wi Magnetic Dipole Transitions Spectroscopic-Quality Parameters of Insulating Laser Crystals with Ln3+ Activators References Multiphonon 4fN-4fN Nonradiative Transitions of Ln3+ Activators in Laser Crystals Principal Mechanisms of the Modern Theory of Nonradiative Relaxation of Ln3+ Ions in Crystals Energy-Gap Law - Dependence of WJJc on DEJJc References MULTILEVEL OPERATING LASER SCHEMES FOR THE EXCITATION OF STIMULATED EMISSION IN ACTIVATED CRYSTALS Cascade Operating Schemes for Crystalline Lasers Cascade Laser Schemes for Crystals Doped with Ln3+ Activators Features of Cascade Generation of the Ln3+ Ions in Crystals Cross-Cascade Laser Schemes for Crystals Doped with Ln3+ Activators References Sensitizing, Deactivating, and Feed-Flowing Operating Schemes for Crystalline Lasers Sensitizing Laser Schemes Deactivating Laser Schemes Feed-Flowing Laser Schemes Laser Action of Unlike Ln3+ Ion-Doped Crystals References Stepwise Laser Operating Schemes for Crystals Doped with Ln3+ Activator Ions Upconversion and Stimulated Emission of Ln3+ Ions in Crystals at High-Level Energy Excitation Upconversion Operating Laser Schemes for Er3+ Ion-Doped Crystals Operating Laser Schemes with Stepwise Absorption of Pump Quanta for YAlO3 and LiYF4 Crystals Doped with Er3+ Ions References Cross-Relaxation Operating Schemes for Crystalline Lasers Cross-Relaxation Laser Operating Schemes with Quantum Efficiency Equal to 1 Cross-Relaxation Laser Operating Schemes with Quantum Efficiency Equal to 2 Cross-Relaxation Laser Operating Schemes with Quantum Efficiency Equal to 3 Three-Micron 5I6 (R)yy5I7 Laser Channel of Ho3+ Ions in the BaYb2F8 Crystal References Laser Operating Schemes with Strong Depopulation of the Ground States of Generating Ln3+ Ions Ground-State Lifting - a Way to Increase Crystalline-Laser Efficiency Laser Action of Ln3+ Ions in Insulating Crystals Under Condition of Ground-State-Level Depletion Photon-Avalanche Phenomena in Laser Crystals with Ln3+ Activators References NOVEL AND PROMISING TECHNOLOGIES IN THE PHYSICS AND TECHNIQUE OF CRYSTALLINE LASERS New Generation of Crystalline Lasers Laser Action of Crystals Doped with Ln3+ Ions under Selective Laser Pumping Miniature Crystalline Lasers with High Density of Waveguiding Laser Pumping Crystalline Lasers with Self-Frequency Conversion Solar-Pumped Crystalline Lasers References Concluding Remarks The Current State in Laser-Diode-Pumped Crystalline Laser Development (Table Data) Up-to-Date Survey of Crystalline Upconversion Lasers (Table Data) Praseodymium Crystalline Lasers for the Creation of "White" Laser Light References Appendix A: Crystalline Hosts and Lasing Ions Index

Crystalline Lasers: Physical Processes and Operating Schemes

The control of luminous radiation has extremely important implications for modern and future technologies as well as in medicine. In this Review, we detail chemical structures and their relevant photophysical features for various groups of materials, including organic dyes such as metalloporphyrins and metallophthalocyanines (and derivatives), other common organic materials, mixed metal complexes and clusters, fullerenes, dendrimeric nanocomposites, polymeric materials (organic and/or inorganic), inorganic semiconductors, and other nanoscopic materials, utilized or potentially useful for the realization of devices able to filter in a smart way an external radiation. The concept of smart is referred to the characteristic of those materials that are capable to filter the radiation in a dynamic way without the need of an ancillary system for the activation of the required transmission change. In particular, this Review gives emphasis to the nonlinear optical properties of photoactive materials for the functi...

Nonlinear Optical Materials for the Smart Filtering of Optical Radiation.

Deuterated L-arginine phosphate (d-LAP) is a highly transparent monoclinic crystal with attractive properties for efficient frequency conversion. It is grown easily from aqueous solution, and it is phase-matchable for all nonlinear processes where KDP is phase-matchable. Over most of its usable frequency range, it is substantially more efficient than KDP. Crystals grown in large sizes (100 cm/sup 3/) have a high damage threshold, excellent optical quality, are less hygroscopic than KDP, and are easily fabricated into nonlinear devices. Deuterated LAP is attractive for harmonic generation of Nd lasers and for work in the ultraviolet down to about 250 nm. >

Deuterated L-arginine phosphate: a new efficient nonlinear crystal

Application of efficient ultraviolet excimer lasers such as the 248 nm KrF laser to laser fusion requires that long laser pulses be efficiently converted to short pulses at high intensity. The backward Raman amplifier is shown to be a promising candidate for this application. Gain, saturation, and limits to amplifier performance are described. It is shown that pump beams of poor spatial quality may be converted to output beams of high spatial quality. Several common gaseous vibrational Raman scatterers are discussed, and it is shown that a simple KrF-pumped backward Raman amplifier using methane at atmospheric pressure will have a saturation fluence near 1 J/cm2and can produce an output five times as intense as the pump in a ten times shorter pulse with an efficiency of about 50 percent. Design tradeoffs and possible techniques for further improving the performance of such amplifiers are discussed.

Raman pulse compression of excimer lasers for application to laser fusion

High average power frequency conversion using solid-state nonlinear materials is discussed. Recent laboratory experience and new developments in design concepts show that current technology, a few tens of watts, may be extended by several orders of magnitude. For example, using KD*P, efficient doubling (> 70 percent) of Nd:YAG at average powers approaching 100 KW is possible; for doubling to the blue or UV regions the average power may approach 1 MW. Configurations using segmented apertures permit essentially unlimited scaling of average power. High average power is achieved by configuring the nonlinear material as a set of thin plates with a large ratio of surface area to volume, and cooling the exposed surfaces with a flowing gas. The design and material fabrication of such a harmonic generator is well within current technology.

High average power harmonic generation

A technique for frequency conversion of high-power lasers is described which uses two crystals for each conversion step rather than one. The two crystals are oriented so that the waves generated in them are orthogonally polarized. The conversion efficiency of these quadrature arrangements is much less sensitive to laser pulse nonuniformities than that in single-crystal methods. Consequently, very high conversion efficiency is possible for typically nonuniform laser pulses. Realization of the quadrature concept for all types of nonlinear optical processes are described. Data taken on second harmonic generation of Gaussian pulses shows that very high (internal) conversion efficiency is possible ( > 95 percent) over a substantial range of input energy.

Quadrature frequency conversion

The elastic constants and thermoelastic coefficients of silver gallium selenide and deuterated l-arginine phosphate (d-LAP) are reported. Their fracture strength as measured by indentation tests is also reported. These data are used to calculate their thermal fracture resistance, a parameter which is important in high-average-power laser systems. Their thermal fracture resistance is then compared to that of other nonlinear crystals. To the extent that the damage threshold increases with fracture temperature, the data on AgGaSe/sub 2/ and d-LAP are favorable indicators of a higher damage threshold. In particular, the data suggest that d-LAP should compare favorably with other solution-grown materials such as lithium iodate and KDP. Preliminary data on the damage threshold of d-LAP appear to confirm that it is indeed more damage resistant than comparably prepared samples of these other solution-grown materials. >

D. Eimerl

Papers

Deuterated L-arginine phosphate: a new efficient nonlinear crystal

Raman pulse compression of excimer lasers for application to laser fusion

High average power harmonic generation

Quadrature frequency conversion

Elastic constants and thermal fracture of AgGaSe/sub 2/ and d-LAP