Patent Application
20180024389
The present invention relates to the new type Electro-Optical (E-O) crystal elements, its applications and the processes for the preparation thereof. More specifically, the present invention relates to an E-O crystal element showing super-high effective (transverse and longitudinal) linear E-O coefficient and very low half-wave voltage Vπ useful in a wide number of modulation, communication, laser, and electro-optical industrial uses.
Recently PMN-PT based ferroelectric relaxor crystals have been well developed because of its super-high piezoelectric properties such as electrical strains an order higher than conventional piezoelectric materials and the electro-mechanical coupling factor over 90%. These crystals have been used for piezoelectric applications, especially for acoustic transduction devices, such as ultrasound imaging and sonar transducers. The very anisotropic piezoelectric characteristics of <011> poled PMN-PT and/or PZN-PT based crystals have been well documented. These can be noted in Applicant's prior publications, the entire contents of which are incorporated herein fully by reference:
The linear E-O effects of <001> poled and <111> poled PMN-PT and PZN-PT ferroelectric crystals above have been reported, but the results were not encouraged or promoted as inoperative for commercial uses. These results were noted in the publications below, the entire contents of which are also incorporated herein fully by reference.
The major reason is the light scattering from multi-domain walls and the instability of <111> poled single domain status and that all the reported works were limited in optical uniaxial crystals of the PMN-PT or PZN-PT based solid solutions.
The present invention relates to E-O crystal elements of ultra-high effective E-O coefficient γc and very low half-wave voltage Vπ in PMN-PT and PZN-PT based ferroelectric single crystal materials. The invention gives new E-O crystal elements and related E-O crystal devices with benefit merits including:
The invention enables the commercially application of the invented E-O crystal elements in a variety of the E-O crystal devices as a new generation of E-O crystal elements. It is especially applicable to E-O switching, E-O phase modulation, E-O amplitude modulation, laser beam modulation and optical birefringence devices.
The present invention also relates to the new type Electro-Optical (E-O) crystal elements, its applications and the processes for the preparation thereof. More specifically, the present invention relates to an E-O crystal element showing high effective transverse and longitudinal linear E-O coefficient and very low half-wave voltage Vπ useful in a wide number of modulation, communication, laser, and industrial uses.
The present invention also relates to an Electro-Optical (E-O) crystal element, (which can be made from doped or un-doped PMN-PT, PIN-PMN-PT or PZN-PT ferroelectric crystals) showing super-high linear E-O coefficient γc, e.g., transverse effective linear E-O coefficient γTc more than 1100 pm/V and longitudinal effective linear E-O coefficient γlc up to 527 pm/V, which results in a very low half-wavelength voltage Vlπ below 200V and VTπ below 87V in a wide number of modulation, communication, laser, and industrial uses. The present invention also notes that the proposed crystal element is operative as a means for providing the results therein, stated differently, the proposed crystal elements are means for providing a transverse effective linear E-O coefficient γTc more than 1100 pm/V and longitudinal effective linear E-O coefficient γlc up to 527 pm/V, which results in a very low half-wavelength voltage Vlπ below 200V and VTπ below 87V, in products, systems, and apparatus containing the same following operative configuration.
The E-O single crystal materials can be selected from PMN-PT (Lead Magnesium Niobate-Lead Titanate) or PIN-PMN-PT (Lead Indium niobate-Lead magnesium Niobate-Lead Titanate) or PZN-PT (Lead Zinc Niobate-Lead Titanate) or doped crystals above. The invention particularly relates to a repole-able design, i.e., applied electrical field parallel to the poling direction <011> in the crystals. The E-O crystal elements show (1) the effective transverse linear E-O coefficient γTc as high as the range of 350˜1100 pm/V (operating temperature from −30 C to 85 C) and very low half-wavelength voltage VTπ less than 45 V (l/d=1), and (2) the effective longitudinal linear E-O coefficient γlc as high as in the range of 280˜800 pm/V (operating temperature from −30 C to 110 C) with very low half-wave voltage Vlπ less than 300V, and preferably less than about 200V, and more preferably less than about 150V. The ultra-high effective E-O coefficient γc and very low Vπ in additional to the nature of re-poling capability enable the invented crystal elements to be used in a variety of the E-O devices as a new generation of E-O crystal elements. It is especially applicable to, but not limited to, E-O switching, E-O phase modulation, E-O amplitude modulation, laser beam modulation and optical birefringence devices.
In one aspect of the present invention the following example was provided as a transverse mode E-O crystal element as recited in claim 4 was tested in the configuration of transverse mode E-O amplitude modulation as recited in claim 12 (see
According to one aspect of the present invention, there is provided a method of producing an electro-optical crystal element, comprising the steps of: preparing a ferroelectric crystal having a chemical composition represented by one of the chemical formulas:
Pb(Mg1/3Nb2/3)1-xTixO3 where x is defined as 0.22 to 0.38 (I)
or
Pb(Zn1/3Nb2/3)1-yTiyO3 where y is defined as 0.04 to 0.11, (II)
According to another aspect of the present invention, there is provided a method of producing an electro-optical crystal element, wherein: the step of polarizing results in one of a single domain and a multi-nano-domain structure.
According to another aspect of the present invention, there is provided a method of producing an electro-optical crystal element, further comprising the steps of: conducting a dicing of the prepared crystal element, and conducting a polishing and an optical finishing of the crystal element, thereby forming the electro-optical crystal element.
According to another aspect of the present invention, there is provided a method of producing an electro-optical crystal element, wherein: further comprising the steps of: electroding the crystal element.
According to another aspect of the present invention, there is provided a method of producing an electro-optical crystal element, wherein: providing a transverse mode crystal element, and the transverse mode crystal element providing <011> polarization and giving the transverse effective E-O coefficient γTc more than 527 pm/V and half-wave voltage VTπ less than 87.5 V (l/d=1) at room temperature 20° C.
According to another aspect of the present invention, there is provided a method of producing an electro-optical crystal element, wherein: providing a longitudinal mode crystal element, coating a transparent electrodes on the longitudinal mode crystal element, and the longitudinal mode crystal element providing <011> polarization of longitudinal effective E-O coefficient γlc more than 427 pm/V and Vlπ less than 300 V at room temperature 20° C.
According to another aspect of the present invention, there is provided a method of producing an electro-optical crystal element, comprising the steps of: preparing a ferroelectric crystal having a chemical composition represented by the chemical formula:
y*[Pb(In1/2Nb1/2)O3]-(1-y)*[Pb(Mg1/3Nb2/3)1-xTixO3] (III)
According to another aspect of the present invention, there is provided a method of producing an electro-optical crystal element, according to formula IH, further comprising the steps of: providing a transverse mode crystal element, and the transverse mode crystal element providing <011> polarization and giving the transverse effective E-O coefficient γTc above 500 pm/V and half-wave voltage VTπ less than 12 V (l/d=7) at room temperature 20° C.
According to another aspect of the present invention, there is provided a method of producing an electro-optical crystal element, further comprising the steps of providing a longitudinal mode crystal element, coating a transparent electrode on the longitudinal mode crystal element, and the longitudinal mode crystal element providing <011> polarization of longitudinal effective E-O coefficient γlc above 427 pm/V and Vlπ less than 300 V at room temperature 20° C.
According to another aspect of the present invention, there is provided an electro-optical system, the system being one of an amplitude modulator and a phase modulator, comprising: a longitudinal mode electro-optical crystal element produced by a method according to formula III, and the longitudinal mode electro-optical crystal element including means for providing <011> polarization of longitudinal effective E-O coefficient γlc above 427 pm/V and Vlπ less than 300 V at room temperature 20° C.
According to another aspect of the present invention, there is provided an electro-optical system, the system being one of an amplitude modulator and a phase modulator, comprising: a transverse mode electro-optical crystal element produced by a method according to formulas I or II, and the transverse mode electro-optical crystal element including means for providing <011> polarization and giving the transverse effective E-O coefficient γTc above 500 pm/V and half-wave voltage VTπ less than 87.5 V (l/d=1) at room temperature 20° C.
According to another aspect of the present invention, there is provided an electro-optical system, the system being one of an amplitude modulator and a phase modulator, comprising: a transverse mode electro-optical crystal element produced by a method acceding to formula III, and the transverse mode electro-optical crystal element including means for providing <011> polarization and giving the transverse effective E-O coefficient γTc above 500 pm/V and half-wave voltage VTπ less than 12 V (l/d=7) at room temperature 20° C.
According to another aspect of the present invention, there is provided an electro-optical modulator system for laser beams, comprising: a Mach-Zehnder-type interferometer modulator on an (011) surface of an optical electrical crystal element, and the optical electrical crystal clement produced by a method according to one of formulas I, II, and III.
The above and other optional and adaptive aspects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
Reference will now be made in detail to aspects of the invention. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. The word ‘couple’ and similar terms do not necessarily denote direct and immediate connections, but also include connections through intermediate elements or devices. For purposes of convenience and clarity only, directional (up/down, etc.) or motional (forward/back, etc.) terms may be used with respect to the drawings. These and similar directional terms should not be construed to limit the scope in any manner. It will also be understood that other embodiments may be utilized without departing from the scope of the present invention, and that the detailed description is not to be taken in a limiting sense, and that elements may be differently positioned, or otherwise noted as in the appended claims without requirements of the written description being required thereto.
Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments of the present invention; however, the order of description should not be construed to imply that these operations are order dependent.
The present invention provides an Electro-Optical (E-O) crystal element, applications and the processes for the preparation thereof, including the use of the same in further systems, lasers, and modulators, as will be discussed.
More specifically, the present invention relates to an E-O crystal element showing high effective transverse and longitudinal linear E-O coefficient and very low half-wavelength voltage Vπ useful in a wide number of modulation, communication, laser, and industrial uses.
The ferroelectric single crystal materials can be PMN-PT (Lead Magnesium Niobate-Lead Titanate) or PIN-PMN-PT (Lead Indium niobate-Lead magnesium Niobate-Lead Titanate) or PZN-PT (Lead Zinc Niobate-Lead Titanate) and/or doped crystals above. The invention particularly relates to a repole-able design <011> -poled (cubic notation) ferroelectric crystals mentioned above. The optical transmittance of the poled crystals is transparent from 0.41 μm continues into the IR region at least through 5 μm without any noticeable absorption bands. The E-O crystals give super-high effective/apparent electro-optic coefficient γc/γ*c and revy low half-wave voltage below 87 V. This <011> repole-able characteristic is strategically important for the practical applications in terms of reliability and convenience for uses. Another merit of the repole-able configuration is the low cost for the fabrication of E-O crystal elements. We have discovered that, the <011>-poled E-O crystal elements show (1) the effective transverse linear E-O coefficient γTc as high as the range of 350˜1100 pm/V (operating temperature from −30 C to 110 C) and very low half-wave voltage VTπ less than 85 V (l/d=1) and less than 12V (l/d=7), and (2) the effective longitudinal linear E-O coefficient γlc as high as in the range of 280˜800 pm/V (operating temperature from −30 C to 110 C) with very low half-wave voltage Vlπ less than 315V. The ultra-high effective E-O coefficient γc and very low Vπ in additional to the nature of re-poling capability enable the invented crystal elements to be used in a variety of the E-O devices as a new generation of E-O crystal elements. It is especially applicable to E-O switching, E-O phase modulation, E-O amplitude modulation, laser beam modulation, tunable filter and optical birefringence devices.
Referring now to
Referring further now to
Note: <001> poling results in 4 mm symmetric multi-domain structure and property and <111> poling results in 3 m symmetric single domain and property, both must be optical uniaxial, whereas the <011> poling must result in optical biaxial status this is a substantial difference that must be recognized and has not been in the art.
Table 1 gives a list of commercial E-O crystals
The E-O single crystal materials can be PMN-PT (Lead Magnesium Niobate-Lead Titanate) or PIN-PMN-PT (Lead Indium niobate-Lead magnesium Niobate-Lead Titanate) or PZN-PT (Lead Zinc Niobate-Lead Titanate) and/or doped crystals of the above.
Experimental Sample 1:
A transverse mode E-O crystal element with composition: 67.5% PMN-32.5% PT single crystal element. The cut direction, poling direction and configuration of incident light and crystallographic orientation are showing in
Data Tested at Different Temperatures
Experimental Sample 2:
A longitudinal mode E-O crystal element with composition: 67.5% PMN-32.5% PT single crystal element. The cut direction, poling direction and configuration of incident light and crystallographic orientation are showing in
Experimental Sample 3
A longitudinal mode E-O crystal element with composition: 24% PIN52.4% PMN-23.6% PT single crystal element. The cut direction, poling direction and configuration of incident light and crystallographic orientation are showing in
Experimental Sample 4
A transverse mode E-O crystal element with composition: 24% PIN52.4% PMN-23.6% PT single crystal element. The cut direction, poling direction and configuration of incident light and crystallographic orientation are showing in
Referring specifically now to
Additionally referring now to
The present invention also provides the use of the disclosed E-O elements in commercial E-O crystal element applications containing a variety of the E-O crystal devices as a new generation of E-O crystal elements. It is especially applicable to E-O switching systems and methods, E-O phase modulation systems and methods, E-O amplitude modulation systems and methods, laser beam modulation and optical birefringence devices and related systems and methods, and the accompanying systems that include the same.
The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its structure and its operation together with the additional object and advantages thereof will best be understood from the following description of the preferred embodiment of the present invention when read in conjunction with the accompanying drawings. Unless specifically noted, it is intended that the words and phrases in the specification and claims be given the ordinary and accustomed meaning to those of ordinary skill in the applicable art or arts. If any other meaning is intended, the specification will specifically state that a special meaning is being applied to a word or phrase.
Moreover, even if the provisions of 35 U.S.C. 112, paragraph 6, are invoked to define the inventions, it is intended that the inventions not be limited only to the specific structure, material or acts that are described in the preferred embodiments, but in addition, include any and all structures, materials or acts that perform the claimed function, along with any and all known or later-developed equivalent structures, materials or acts for performing the claimed function.
In the claims, means- or step-plus-function clauses are intended to cover the structures described or suggested herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, for example, although a nail, a screw, and a bolt may not be structural equivalents in that a nail relies on friction between a wooden part and a cylindrical surface, a screw's helical surface positively engages the wooden part, and a bolt's head and nut compress opposite sides of a wooden part, in the environment of fastening wooden parts, a nail, a screw, and a bolt may be readily understood by those skilled in the art as equivalent structures.
Having described at least one of the preferred embodiments of the present invention with reference to the accompanying drawings, it will be apparent to those skills that the invention is not limited to those precise embodiments, and that various modifications and variations can be made in the presently disclosed system without departing from the scope or spirit of the invention. Thus, it is intended that the present disclosure cover modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.
This application is a continuation of U.S. Ser. No. 14/390,522 filed Oct. 3, 2014 which in turn claims priority from Ser. No. PCT/US2013/035343 filed Apr. 4, 2013 which in turn claims priority from U.S. Prov. No. 61/686,350 filed Apr. 4, 2012, and U.S. Prov. Ser. No. 61/802,796 filed Mar. 18, 2013, the entire contents of each of which is fully incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61686350 | Apr 2012 | US | |
| 61802796 | Mar 2013 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15006762 | Jan 2016 | US |
| Child | 15487478 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14390522 | Oct 2014 | US |
| Child | 15006762 | US |
