JPH02199405A - Laser attenuation optical filter - Google Patents

Abstract

PURPOSE: To embody an optical filter which highly absorbs incident laser radiations and attenuates the radiations at 532nm by an optical filter consisting of a light transparent polymer matrix contg. platinum deuteroporphyrin IX dimethyl ester. CONSTITUTION: The optical filter consisting of the light transparent polymer matrix contg. the platinum deuteroporphyrin IX dimethyl ester highly absorbs the incident laser radiations at 532nm and simultaneously has high transmittability at the neighboring wavelength in a visible region. The suitable light transparent, more preferably transparent materials, for example, polycarbonate, acryl polymers, etc., are added and mixed with the compd. contg. deuteroporphyrin and the mixture is formed by molding, extruding, casting, etc., for forming a solid sheet, plate, lens, protective surface, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION The present invention relates to optical filters for attenuating incident laser radiation, particularly neodymium YAG at 532 nm.
This invention relates to a filter for absorbing double radiation.

In some applications, it is necessary to attenuate incident laser radiation at one or more wavelengths while transmitting a substantial portion of the incident laser radiation at other wavelengths. One such application is military security. Since laser radiation is extremely intense, the attenuation at the laser wavelength must be correspondingly large, and for this type of filter an optical density of 61 or higher at the laser wavelength is typical. be. In order to meet the dual requirements of high attenuation at the laser wavelength and near-wavelength transmission at neighboring wavelengths, the filter must have extremely sharp cutoff characteristics.

Optical filters are usually made by mixing one or more compounds selected for their absorption properties into a suitable optically transparent matrix, especially a polymeric matrix, such as polycarbonate. To be useful for such applications, an absorber must have absorption at the desired wavelength, as well as absorption at the desired wavelength.
It must have some properties. The compound should be soluble in the matrix and should be compatible with the matrix and any other additives. The compound must be stable enough to be incorporated into the desired matrix and used therein without significant deterioration. The compound must also be easily synthesized on the desired scale.

McKoy et al. No. 4,622,174 uses metal porphyrins, specifically platinum octaethylporphyrin (Pt0EP) for 532 nm neodymium YAG unduplicated radiation absorption and 694 nm ruby VR.
Vanadyl phthalonanine (VOPc) for radiation absorption
Discloses a transparent protective armor containing the following:

()(, rdon's US Li% Permit No. 4,657,345 states that the absorbent is not uniformly distributed throughout,
A similar barrier is disclosed that is diffused onto the surface of the matrix. Pt0EP strongly absorbs at 532 nll1, but its maximum absorption does not coincide with that wavelength and occurs at a slightly longer wavelength of about 537 nm. The absorption peak is extremely sharp, so
This means that to obtain an optical density given by the laser wavelength, an extra absorber must be used if the absorption maximum coincides with the laser wavelength. Not only is the absorber relatively expensive since platinum is used, but the resulting filter has low transmittance at other wavelengths due to the bulk of the material used.

[Summary of the invention]

An object of the present invention is to provide an optical filter that absorbs strongly at 532 nm.

Another object of the invention is that at other wavelengths the radiation has a substantial f.
An object of the present invention is to provide an optical filter that transmits tt.

A further object of the invention is to provide an optical filter which may contain other additives for absorption at other wavelengths.

Still another object is to provide an optical filter that is easy to manufacture and inexpensive.

Generally speaking, the present invention formally relates to dimethyl 3.7.
1:2,17-tetramethyl-21H223H-porphyrin-2,18-diglobionetoplatinum (n),
Also contemplated is an optical filter comprising a light-transmissive, preferably transparent, polymer matrix containing a compound known, although not formally known, as platinum deuteroporphyrin dimethyl ester or PtDPIXDME. The manufacturing method is Milgrom, Polyhedron.
, 4 r p. 1661 (1985).
, which is almost exactly at the wavelength 532n
It corresponds to the Rays radiation of m. As a result, to achieve the full optical density given at 532 nm, a smaller amount of this compound is required than, for example, Pt0EP. Not only does it require less platinum as a starting material, but the filter transmittance for nearby wavelengths is high.

In case of use, the scuteloporphyrin compound can be formed into a suitable light-transmissive, preferably transparent material by known methods such as molding, extrusion, casting, etc. to make solid lenses, plates, lenses, protective surfaces, etc. For example polycarbonates, acrylic polymers such as poly(methylmethacrylate), vinyl polymers such as poly(vinyl chloride), poly(allyl diglycol carbonate) and cellulose derivatives, preferably esters such as cellulose acetate,
It may also be mixed into a matrix or film of cellulose propionate, cellulose butyrate, etc.

The amount of absorber used in the matrix depends on the thickness of the matrix and the desired optical density at the Rede wavelength, according to the Beer-Lambert law A = OD = -4og T/TO = αbc [where A is a specific is the absorbance, or optical density (OD), due to the presence of the absorber at that wavelength, T is the transmittance of the filter with the absorber at that wavelength, and To is the transmittance of the filter without the absorber at that wavelength. where α is the mass absorption coefficient of the absorber at that wavelength in the matrix (L/(ji-cm)), and b is the length of the path through the matrix (cm) and c
is the mass concentration of the absorbent in the base material]. Similarly, the Beer-Lambert law is A = eb Cm [where A and b are defined above, and C
is the molar extinction coefficient of the absorbent in the matrix at the wavelength in question (L/(mot-clll)), and Cm is the molar concentration of the absorbent in the matrix (mot/L). May be expressed. Preferably, the matrix should contain sufficient absorber to have an optical density of about 2 at the laser wavelength.

More preferably, the filter should have an optical density of 3 or greater at the laser wavelength.

The compound may be used with other additives such as dyes, infrared absorbers, etc. that do not adversely affect the compound or its absorption properties.
It may be used together with ultraviolet absorbers and stabilizers. In particular, the scuteloporphyrin compound is vanadyl phthalocyanine (VOPc), e.g. unsubstituted VOP
c or preferably in combination with a further soluble substituted VOPc such as vanadyltetra-4-tert-butylphthalocyanine for absorption total addition at 694 nm. This compound also has a neodymium Rede wavelength of 106
For absorption at 4 nm, it may be combined with tris(p-dialkylaminophenyl)aminium salts, especially tris(p-diethylaminophenyl)-aminium hexafluoroantimonate. If the latter compound is used with poly(allyl diglycol carbonate), preferably
It should be introduced into the matrix after polymerization, for example by dyeing.

Schuteroporphyrin, compound from unmetallized precursor, Schuteroporphyrin dimethyl ester, MitgromX Polyhedron, 4e
It may be produced by the method described on page 1661 (1985). If we use vanadyltetra-4-tert-butylphthaloneanine as the other polymer for absorption at 694 nm, it is better than 4-tetra-butylphthalonitrile and vanadium trichloride, as described by Law r Inorg.
, Chem, +24+1778 pages (1985)
It may be manufactured by the method described in .

Alternatively, the vanadyl compound may be prepared from 4-tetra-butylphthalic acid and vanadium sulfate.

U.S. Pat. No. 3,400,156 to Mitionis et al. describes the preparation of tris(p-dialkylaminophenyl)aminium salts and their incorporation into plastics as infrared absorbers. U.S. Patent No. 3 of 5usi et al.
, 341.464 fully describes the preparation and use of tris(p-dialkylaminophenyl)aminium hexafluoroarsenate and hexafluoroantimonate.

[Description of preferred Geki-sama]

Example 1 Platinum deuteroporphyrin dimethyl ester (first
Figure) is MIZgrOm + Polyhedron l
4 + p. 1661 (1985).

This compound is dissolved in 100 mg of 2.7 m9ffi pyridine and placed in an absorption cell with a thickness of 1 crft. 533.5
The extinction coefficient C measured with rllIl is 41,0001/
It is mot-cm. The absorption spectrum of this compound in pyridine solution is shown in FIG. Maximum absorption is 533.5
nm (A=1-488), 500.5 nm
(0,479) and 384-Onm (2-482)
observed in The minimum absorption is 649.5 nm (0,019
), 513. Onm (0,276) and 465.5
found in nm (0-164).

Example 2 500 g of porphyrin (0.1949k, polycarbonate) of Example 1 and these two materials are mixed in a mixer for 1 minute. The mixture is dried at 250° F. for 11/2 hours and injection molded into disks [1,038 inches thick]. The injection pressure is varied between a high pressure of 1800 psi and a low pressure of 1500 psi. Clamp pressure is 2100
psi, cycle time is 17.7 seconds. The nozzle temperature is 458°F1, 450°F' at the front of the cylinder, and 460°F' at the rear of the cylinder.

The disk has strong absorption at 532 nm ('oD = 1.
8) and showed high light transmittance at other wavelengths in the visible region. The transmission spectrum of the disk is shown in FIG. The disk shows high transmission of visible light, while 562n
It serves as a "7-angle notch" reso filter in m. Photobic light transmission (illuminance C) is 53.8 inches.

Example 6 0.0165 g of vanadyl tetra-4-tert-butylphthalonanine (Figure 2) was added to the mixture of Example 2. The entire mixture is injection molded to form a plate having a thickness of 0.1101 mm. The plate is 3.4.694.3 at 532 nm
It exhibits an optical density of 1.5 in nm (Ruby Rede wavelength) and a photobic light transmission of 27.9%.

It is used as a highly optically transparent laser filter that simultaneously filters out the laser radiation at 532 nm and 694.3 nm.

Example 4 To the mixture of Example 2 is charged 0.5269 of tris(p-diethylami/phenyl)aminium hexafluoroarsenate monate (U.S. Pat. No. 3,341,464).

This mixture was fully injection molded to produce a 0-073 inch thick plate with an optical density of 2.7 at 532 nm and 2.8 at IO64 nm (neodymium YAG laser wavelength). It serves as a laser filter with high light transmission, simultaneously filtering out the laser radiation of the stated wavelengths.

It will be seen that the objectives of the invention have been achieved. The present optical filter absorbs strongly at 532 nm and at the same time has high transmittance at nearby wavelengths in the visible region.

The light-absorbing compounds of the present filters can be mixed into the plastic polymer matrix and may be used together with other additives, such as light absorbers.

It will be appreciated that some features and subcombinations may be useful and may be employed without reference to other features and combinations. This is contemplated by and within the scope of the claims. It will be obvious that various further changes may be made in the details within the scope of the claims and without departing from the spirit of the invention. It is therefore understood that the invention is not limited to the details shown above.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the structural formula of platinum deuteroporphyrin dimethyl ester, Figure 2 is a diagram showing the structural formula of vanadyl tetra-4-tert-butylphthalonanine, and Figure 6 is a diagram showing the structural formula of vanadyl tetra-4-tert-butylphthalonanine. is a diagram showing the absorption spectrum of the compound shown in FIG. 1 in a solution, and FIG. 4 is a diagram showing the transmission spectrum of an optical filter containing the compound shown in FIG. 1.

Claims (20)

[Claims] (1) An optical filter made of a light-transmitting polymer matrix containing platinum dieuteroporphyrin IX dimethyl ester. (2) The optical filter according to item (1), wherein the polymer matrix is polycarbonate. (3) The optical filter according to item (1), wherein the compound is uniformly distributed throughout the polymer matrix. (4) The polymer matrix is transparent (
The optical filter described in 1). (5) The optical filter according to item (1), wherein the polymer matrix further contains vanadyl phthalocyanine. (6) The vanadyl phthalocyanine is vanadyl tetra-
The preceding item (5), which is 4-tert-butylphthalocyanine,
). (7) The optical filter according to item (1), wherein the polymer matrix further contains a tris(p-dialkylaminophenyl)aminium salt. (8) The optical filter according to item (7), wherein the aminium salt is tris(p-diethylaminophenyl) aminium hexafluoroantimonate. (9) The optical filter according to item (1), wherein the polymer matrix contains vanadyl phthalocyanine and tris(p-dialkylaminophenyl) aminium salt. (10) The optical filter according to item (1), having an optical density of at least about 2 at 532 nm. (11) The optical filter according to item (1), which has an optical density of at least about 3 at 562 nm. (12) inserting an optical filter containing the compound platinum deuteroporphyrin IX dimethyl ester between the laser radiation source and the object, wavelength 532n;
A method of protecting objects from exposure to laser radiation with m. (13) The method according to item (12), wherein the filter is a light-transmissive polymer matrix containing the compound. (14) The method according to (13) above, wherein the polymer matrix is polycarbonate. (15) The method according to item (12), wherein the compound is uniformly distributed throughout the thickness of the filter. (16) The method according to item (12), wherein the filter is transparent. (17) The method according to item (12), wherein the filter further contains vanadyl phthalocyanine. (18) The above-mentioned item (12), wherein the filter further contains a tris(p-dialkylaminophenyl) aminium salt.
The method described in. (19) The method according to item (12), wherein the filter further contains vanadyl phthalocyanine and tris(p-dialkylaminophenyl) aminium salt. (20) The method according to (12), wherein the filter has an optical density of at least about 2 at 532 nm.