Organic Nonlinear Crystal Research Articles

Growth and characterization of deuterated L-arginine phosphate monohydrate, a new nonlinear crystal, for efficient harmonic generation of fusion experiment lasers

L-arginine phosphate monohydrate (LAP) is a promising nonlinear organic crystal for higher harmonic generation in place of the conventional KDP. It has a large absorption at 1.06 μm. Deuterated LAP (DLAP) has been synthesized to decrease this absorption. The absorption coefficient was reduced from 0.09 to 0.02 cm -1 Microbes which easily multiply in the growth solution were successfully inhibited by Hadding H 2 O 2 . Damage thresholds of LAP and DLAP crystals are much higher than that of KDP and fused silica. We suggest that DLAP can be used in place of KDP in high power lasers.

Large second harmonic generation from mixtures of para-nitroaniline and its N-alkyl derivatives

We have investigated nonlinear organic mixtures of para-nitroaniline (p-NA) and its N-alkyl derivatives, by measuring the second harmonic generation (SHG) from the powder samples. The SHG powder test shows that the mixtures of p-NA and N-isopropyl-4-NA (Pr iNA) or N-n-propyl-4-NA (Pr nNA) or N-n-butyl-4-NA (Bu nNA) have exceedingly large SHG activity, although the individual compound has relatively small or no SHG activity. The measured SHG intensities of the three mixtures come up to the maximum values of 416, 270, and 271 times larger than that of urea, when the mixing weight ratios to p-NA are 0.5, 0.1, and 0.05, respectively. That is, the mixture of Pr iNA and p-NA is found to have second largest powder efficiency reported to date. This result indicates a new direction in the field of co-crystallization of organic molecules to generate highly nonlinear organic crystals.

Diamond turning of L-arginine phosphate, a new organic nonlinear crystal

We have demonstrated that single point diamond turning can be used to generate high optical quality finished surfaces on a new organic nonlinear crystal, L-arginine phosphate (LAP). The proper choice of cutting conditions can produce surfaces with <5-A rms local roughness. Local softening or melting near the cutting tool tip may play a key role in the machining process by ensuring that material is removed by ductile cutting rather than brittle fracture. At the same time, the low melting temperature of LAP makes lubrication and cooling especially important to prevent extensive melting and tool fouling. In spite of the presence of a weak cleavage plane in LAP, the surface quality is relatively insensitive to crystallographic orientation. Tool wear is apparently negligible, so that surface flatness is governed by the stability of the diamond turning machine. These results suggest that it may be possible to fabricate large aperture LAP harmonic converters for use in inertial confinement fusion lasers.

Single Point Diamond Turning of an Organic Nonlinear Crystal, L-Arginine Phosphate

We have demonstrated that single point diamond turning can be used to generated high optical quality finished surfaces on a new organic nonlinear crystal, L-arginine phosphate (LAP). The proper choice of cutting conditions can produce surfaces with less than 5 angstroms rms surface roughness. Local softening or melting near the cutting tool tip may play a key role in the machining process by ensuring that material is removed by ductile cutting rather than brittle fracture. At the same time, the low melting temperature of LAP makes lubrication and cooling especially important to prevent extensive melting and tool fouling. In spite of the presence of a weak cleavage plane in LAP, the surface quality is relatively insensitive to crystallographic orientation. Tool wear is apparently negligible, so that surface flatness is governed by the stability of the diamond turning machine. Data on residual subsurface strain and preliminary measurements of the optical damage thresholds of diamond turned LAP surfaces will be presented.

Growth and second harmonic generation of deuterated L-arginine phosphate monohydrate crystal.

L-arginine phosphate monohydrate (LAP) is a promising nonlinear organic crystal for higher harmonic generator in place of a KDP crystal LAP has a large absorption at 1.06μm. We synthe-sized deuterated LAP (DLAP). The absorption coefficient was reduced to 0.02 cm-1 from 0.09 cm-1. The cut-off wavelength of ultra-violet light was 0.26μm. The phase-matching angles for this biaxial crystal were calculated using measured refractive indices at 1.06μm and 0.53μm. The measured angles at which maximum output of second harmonics for Type I and Type II were in fairly good agreement with the calculation. The effective nonlinear optical coefficient was almost twice and the acceptance angle was almost a half of the KDP crystal. We can say that DLAP can be used in place of KDP in high power lasers.

Parametric amplification sampling spectroscopy of luminescence at the subpicosecond time scale in the 1–1.6 μm spectral range

A new method for time-resolved luminescence spectroscopy with subpicosecond resolution is proposed in the 1–1.6 μm spectral range, using parametric amplification in a highly nonlinear organic crystal. This technique is used to characterize the luminescence of an infrared dye and of an InGaAs-InAlAs multiple quantum well structure.

A new phase matchable nonlinear optical crystal-L-arginine phosphate monohydrate (LAP)

In search of new organic nonlinear optic crystals, aromatic compounds with donor and acceptor substituents are extensively studied. Some new crystals with large nonlinear coefficient have been reported. This kind of crystals is usually not useful in ultraviolet region, because the distance between energy levels in conjugated π bonds gets smaller due to the strong conjugation effect. In exploring new organic nonlinear optic crystals used in ultraviolet region, we have discovered a new phase matchable nonlinear optic organic crystal --L-arginine phosphate monohydrate. Of the size 13×35×35 mm~3 LAP single crystals with good optical quality have been grown by the cooling and evaporating methods. LAP crystal belongs to monoclinic system; its space group is P2_1. It shows the following proper ties: (1) transparency range over 10% extends from 230nm to 1940 nm; over 50% extends from 240nm to 1500 nm; (2) when basic wave is 1064 nm and harmonic wave is 532 nm, the calculated phase matching curved surface belongs to Hobden 's ninth type; (3) SHG intensity of LAP crystal in phase matching direction (θ=57°ρ=-13°phase matching type II) is 3.5 times greater than that of KDP crystal (θ=59°ρ=0°type II). It is worth to note that this direction of LAP crystal will not be one of its maximum effective nonlinear coefficient; (4) when basic waves are 1064 nm and 532 nm, the sum-frequency effect has been observed; (5) the optical damage threshold is higher than 1 GW/cm~2·s at 1064 nm; (6) the stability towards atmospheric moisture is excellent. As a result, LAP crystal is a promising nonlinear optic crystal.

ChemInform Abstract: DEMONSTRATION OF EFFICIENT NONLINEAR OPTICAL CRYSTALS WITH VANISHING MOLECULAR DIPOLE MOMENT: SECOND‐HARMONIC GENERATION IN 3‐METHYL‐4‐NITROPYRIDINE‐1‐OXIDE

AbstractEs werden die Bedingungen untersucht, die eine organische Verbindung besitzen muß, um gute optische Kristalle zu liefern ( ;z.B. hohe Hyperpolarisierbarkeit 1. Ordnung, geeignete Kristallstruktur, ausreichende optische Qualität).

Demonstration of efficient nonlinear optical crystals with vanishing molecular dipole moment: Second-harmonic generation in 3-methyl-4-nitropyridine-1-oxide

Previous research toward more efficient nonlinear optical organic crystals has aimed at increasing the first-order hyperpolarizabilitiy of individual molecular units. We show that the general features derived from these studies (high conjugation, charge transfer, and molecular asymmetry) leave room for the cancellation of the molecular dipole moment. This can be usefully exploited in two directions: improving the crystal growth conditions and a possibility of acting on the crystal point group structure through otherwise hidden parameters. Pyridine-1-oxide, owing to the electronic ’’push–pull’’ property of the N–oxide bond, allows for substitution in the 4 position of donor as well as acceptor groups, among which the nitro group ensures dipole cancellation. The possibility of charge transfer from or toward the N–oxide bond according to the nature of the radical in the 4 position is investigated and confirmed by means of second-harmonic generation experiments in powder or solution (DCFISH) on a number of compounds. 3-methyl-4-nitropyridine-1-oxide is shown to be the best candidate, among related compounds, for crystal growth. A detailed study of its linear and first-order nonlinear properties is presented. Crystalline samples grown in solution are seen to be of excellent optical quality. Its efficiency compares to that of the best available phase- matchable organic crystals [d = (23±3)×10−9 esu]. Besides, the optical broadband phase-matching potential of the crystal could be useful in a number of applications like frequency doubling of ultrashort pulses in the near infrared.

High temperature ultrasonic interferometer: Ukrainskii fizicheskii zhurnal, 9, No. 7, 766 (1964)

Heteroepitaxy of organic second-order nonlinear optical crystal MNBA (4′-nitrobenzylidene-3-acetamino-4-methoxyaniline) on its family crystal MNBA-Et (4,-nitrobenzylidene-3-ethylcarbonylamino-4-methoxyaniline) has been discovered and developed for guided-wave optics; Vapor phase deposition of MNBA on MNBA-Et crystal substrate (MNBA-Et wafer) afforded a single–domained, thin single crystal of MNBA over the whole area of the MNBA-Et wafer exposed (>1.5 cm2), with all the principal axes of refractive indices parallel to those of the wafer. The heteroepitaxy occurs in crystallographically almost coaxial manner. The high quality of MNBA crystal planar waveguide fabricated on (010)(y-cut) MNBA-Et wafer by MBE (Molecular Beam Epitaxy) has been shown by propagation of He-Ne laser light without apparent visible streak. The vapor phase heteroepitaxy has been proposed to be a potential technique which opens up a realistic way to sophisticated guided-wave devices for highly nonlinear organic crystals.

Sonics unite with magnetic glow for automatic billet testing: Iron Age, 194, No. 16, 55 (1964)

Heteroepitaxy of organic second-order nonlinear optical crystal MNBA (4′-nitrobenzylidene-3-acetamino-4-methoxyaniline) on its family crystal MNBA-Et (4,-nitrobenzylidene-3-ethylcarbonylamino-4-methoxyaniline) has been discovered and developed for guided-wave optics; Vapor phase deposition of MNBA on MNBA-Et crystal substrate (MNBA-Et wafer) afforded a single–domained, thin single crystal of MNBA over the whole area of the MNBA-Et wafer exposed (>1.5 cm2), with all the principal axes of refractive indices parallel to those of the wafer. The heteroepitaxy occurs in crystallographically almost coaxial manner. The high quality of MNBA crystal planar waveguide fabricated on (010)(y-cut) MNBA-Et wafer by MBE (Molecular Beam Epitaxy) has been shown by propagation of He-Ne laser light without apparent visible streak. The vapor phase heteroepitaxy has been proposed to be a potential technique which opens up a realistic way to sophisticated guided-wave devices for highly nonlinear organic crystals.