CN1226814C - Method for setting super crystalline lattice all solid state red-yellow-green-blue four-color laser - Google Patents

Abstract

The present invention relates to a superlattice all-solid laser device with four colors of red, yellow, green and blue. Nd: YVO#-[4] crystals are pumped by an LD; 1.064 mu m and 1.342 mu m laser simultaneously oscillate in the way of a straight cavity or shunt fold and is output in the collinear way (shown in the picture 1, the 1.342 mu m laser oscillates between 3 to 6, and the 1.064 mu m laser oscillates between 3 to 7). A non-periodic LiTaO3 superlattice which can simultaneously realize frequency doubling of the 1.064 mu m laser (green) and the 1.342 mu m laser (red), frequency-triple (blue), and the sum frequency of the 1.064 mu m laser and the 1.342 mu m laser (yellow) is put in a temperature control furnace in or out of a cavity to get red, yellow, green and blue laser output simultaneously. The superlattice all-solid laser device with four colors of red, yellow, green and blue has a high application value in the fields of high-brightness laser display, laser rear projection, chromatic laser printing, etc.

Description

The method to set up of super crystal lattice full-solid-state red, yellow, green, blue four look lasers

One, technical field

The present invention relates to a kind of method to set up of super crystal lattice full-solid-state red, yellow, green, blue four look lasers, can excite simultaneously and mix the resonance of Nd ion laser crystal multiwavelength laser, and with superlattice realize a plurality of comprise frequency multiplication and frequently, the nonlinear frequency transformation process of frequency tripling, obtain red, yellow, green, blue four look laser and export simultaneously.

Carrying out the nonlinear optics frequency inverted with the superlattice crystal is the important means that obtains the output of visible light wave range laser.By suitable superlattice microstructure design, utilize its second order nonlinear effect to realize a plurality of frequency conversion (frequency multiplication, frequency tripling and frequency) simultaneously, can realize that the multiwavelength laser in the visible light wave range is exported simultaneously.

Two, background technology

Xiang Guan work before this comprises:

In December calendar year 2001, Nanjing University solid microstructure laboratory (the application unit) Liu Zhaowei, wish that people such as generation is peaceful have delivered on JJAP that " binary cycle counter-rotating domain structure lithium tantalate produces frequency tripling ultraviolet light output (the Ultraviolet generation in a dual-periodic domain invertedstructure in LiTaO of 1.064 μ m laser ₃Crystal by frequency tripling in a 1.064 μ m laser) " LiTaO with bi-period structure reported in article ₃Superlattice are to Nd:YVO ₄The wavelength of emission is the direct frequency triplings of 1.064 μ m laser, produce the result of green glow (0.532 μ m) and ultraviolet light (0.355 μ m) simultaneously, two cycles (basic cycle and modulation period) are respectively l=6.77 μ m, L=51.08 μ m, the peak power of frequency multiplication green glow and frequency tripling ultraviolet light is respectively 344mw and 21mw, and corresponding efficient is respectively 45.4% and 2.7%.

J.Campany delivered on Appl.Phys.Lett. and " produced red, green, blue continuous light laser (Simultaneous generation of red; green, andblue continuous-wave laser radiation in Nd in the acyclic polarized neodymium-doped lithium niobate simultaneously January calendar year 2001 ³⁺-doped aperiodically poled lithiumniobate) " article.Wherein ruddiness (0.686 μ m) and green glow (0.542 μ m) are obtained from frequency multiplication by 1.372 μ m of vibration simultaneously and the first-harmonic of 1.084 μ m respectively, and blue light (0.441 μ m, 0.482 μ m) then is to be obtained with frequency certainly by the pump light of 0.774 μ m and the oscillation light of 1.084 μ m and 1.372 μ m.That article provides is the spectral detection result, and total visible power is about 1mw.And because the aperiodic structure of growth can't be optimized at polychrome output, power output and conversion efficiency and effective output also have suitable distance.

August calendar year 2001, people such as Liu Hui, Zhu Yongyuan delivered the article of " being used for superlattice designs aperiodic (Aperiodic optical superlattice engineered for opticalfrequency conversion) of frequency inverted " at Appl.Phys.Lett., reported superlattice structure method for designing and realize the notional result of multi-wavelength frequency multiplication aperiodic.Can design aperiodic superlattice (counter-rotating farmland) sequence as required provides a plurality of (can be a plurality of arbitrarily in theory greater than three) reciprocal lattice vector to mate the position phase mismatch of a plurality of frequency multiplication processes.To using the single structure superlattice, by the multi-wavelength frequency multiplication and frequently, output had very important value when frequency tripling was realized red, yellow, green, blue four look laser.The patent of the applicant's application (application number: 00119006 and 00119007) also be the basis of used superlattice design among the present invention.

In sum, these research and technology approach all do not relate to and excite Nd:YVO simultaneously ₄The resonance of 1.064 μ m of crystal and the dual-wavelength laser of 1.342 μ m, with the superlattice crystal of a single structure (aperiodic) and frequently simultaneously to 1.064 μ m and 1.342 μ m first-harmonic frequencys multiplication, frequency tripling generation red, yellow, green, blue four look laser effectively export.

Three, summary of the invention

Purpose of the present invention: utilization is mixed the Nd ionic crystals and is excited multiwavelength laser resonance, with superlattice realize a plurality of frequencys multiplication and frequently, directly frequency tripling (refer to the second order nonlinear effect of same crystal finish simultaneously fundamental wave frequency multiplication and frequency doubled light with fundamental wave and obtain frequency tripling frequently) process, obtain the interior multiwavelength laser of visible light wave range simultaneously and export; Especially simultaneously excite Nd:YVO ₄The resonance of 1.064 μ m of crystal and the dual-wavelength laser of 1.342 μ m, and with the lithium tantalate (LiTaO of a single structure (aperiodic) ₃, LT) superlattice are frequency-changer crystal, develop can obtain simultaneously to obtain the small-sized and all solid state laser with practicality that red, yellow, green, blue four look laser are exported simultaneously simultaneously.

The present invention realizes in the manner hereinafter described.

Red, yellow, green, blue four look lasers provided by the invention comprise diode laser (LD) pumping source, Nd ³⁺: YVO ₄Crystal produces the dual wavelength resonant cavity of double wave-length vibration and the superlattice crystal that can realize the ad hoc structure of a plurality of nonlinear frequency transformation processes simultaneously simultaneously.From the Nd ion ⁴F _3/2→ ⁴I _9/2, ⁴I _11/2, ⁴I _13/2, ⁴I _15/2In many spectral lines of energy level transition, select design dual wavelength resonant cavity, obtain the dual wavelength first-harmonic and export simultaneously; Design the LT superlattice of ad hoc structure (aperiodic) then at this dual wavelength first-harmonic.These superlattice can be to Nd:YVO ₄The shorter wavelength laser of emission realizes that frequency multiplication obtains a kind of visible light; Simultaneously also to Nd:YVO ₄The spectral line of the longer wavelength of emission carries out frequency multiplication and frequency tripling, obtains two kinds of visible lights respectively; Consider again to two kinds of spectral lines with frequently obtain another kind of visible light, then obtain four look laser and export simultaneously.Utilize Nd:YVO ₄The laser activity of the excellence of crystal and its two spectral lines of emission ⁴F _3/2→ ⁴I _11/2With ⁴F _3/2→ ⁴I _13/2, design dual wavelength resonant cavity obtains 1.064 μ m and 1.342 μ m dual wavelength first-harmonics are exported simultaneously, designs the LT superlattice of ad hoc structure (aperiodic) then at this dual wavelength first-harmonic.These superlattice can be to Nd:YVO ₄1.064 μ m laser of emission realize that frequency multiplication obtains green glow (0.532 μ m); Also to Nd:YVO ₄1.342 μ m laser of emission are realized frequency multiplication and frequency tripling, obtain the ruddiness of 0.671 μ m and the blue light of 0.447 μ m; Consider to realize simultaneously 1.064 μ m laser and 1.342 μ m laser and frequently, obtain the gold-tinted of 0.593 μ m, thereby construct the small-sized all solid state laser that can realize the output of red, yellow, green, blue four look laser.(1.342 μ m laser vibrate between 3,6 1.064 μ m laser and 1.342 μ m laser are with straight chamber, 1.064 μ m laser vibrates between 3,7, Figure of description Fig. 1) or along separate routes folding mode (1.342 μ m laser vibrate between 13,6,1.064 μ m laser vibrates between 12,7, Figure of description Fig. 2) vibration simultaneously and conllinear output.Adding acousto-optic modulator 5 in the chamber, that 1.342 μ m and 1.064 μ m laser are become is quasi-continuous, improves peak power density and conversion efficiency.Superlattice crystal 10 places temperature control furnace 9, is positioned over outside (in the chamber or) chamber.

The present invention can also adopt mixing Nd ion laser crystal, different pump mode (LD pumping or flash lamp pumping), select the different common resonance of the spectral line of emission, using different super crystal lattice material, different superlattice structure parameters to realize that the visible light of multiple color combination exports simultaneously of different substrates.

Different substrates mix Nd ion laser crystal, comprise Nd:YAG (Nd:Y ₃Al ₅O ₁₂), Nd:YAP (Nd:YAlO ₃) and Nd:GdVO ₄Deng, corresponding ⁴F _3/2→ ⁴I _11/2With ⁴F _3/2→ ⁴I _13/2Stimulated emission cross section and the corresponding wavelength and the Nd:YVO of the spectral line of emission ₄Different, this means, other is mixed the Nd ionic crystals, suitably adjust balance dual wavelength resonance loss, also can realize dual wavelength resonance, the structural parameters of corresponding modify superlattice, they also are applicable to the present invention, and just the red, yellow, green, blue Wavelength of Laser that produces can be slightly different.As the Nd:YAP crystal, corresponding ⁴F _3/2→ ⁴I _11/2With ⁴F _3/2→ ⁴I _13/2Spectral line of emission wavelength be 1.079 μ m and 1.341 μ m, adopt method of the present invention can obtain the gold-tinted that wavelength is 0.670 μ m ruddiness, 0.5981 μ m, the green glow of 0.540 μ m and the blue light of 0.447 μ m.

2.Nd the spectral line of emission of ion is except above-mentioned ⁴F _3/2→ ⁴I _11/2With ⁴F _3/2→ ⁴I _13/2Outside, also comprise ⁴F _3/2→ ⁴I _15/2With ⁴F _3/2→ ⁴I _9/2, if design film system makes ⁴F _3/2→ ⁴I _9/2, ⁴F _3/2→ ⁴I _11/2With ⁴F _3/2→ ⁴I _13/2Resonance can design corresponding superlattice simultaneously, obtains the laser output of multiple color of red, yellow, green, blue and multiple color combination.

3.LT superlattice realize that the method for frequency multiplication and frequency tripling discloses 0019006 and 0019007 referring to background technology and Chinese patent.Except LiTaO ₃Outside the crystal, the present invention also comprises LiNbO ₃, other nonlinear optical crystals such as KTP, RTP superlattice.Their refractive index and dispersion relation difference, so the parameter of superlattice design is also different.

Generally, the optical super lattice material in cycle can only be used for frequency multiplication and single nonlinear frequency transformation processes such as frequency or difference frequency.Realize four kinds of color laser outputs of above-mentioned red, yellow, green, blue, superlattice must provide coupling 1.342 μ m and the 1.064 μ m laser reciprocal lattice vector of frequency multiplication (ruddiness and green glow) respectively, mate 1.342 μ m fundamental waves and its frequency doubled light (ruddiness) and frequently produce the reciprocal lattice vector of frequency tripling (blue light), and the reciprocal lattice vector of 1.342 μ m and 1.064 μ m fundamental waves and frequency (gold-tinted).If the superlattice by four block period structures provide respectively, the corresponding cycle is respectively Λ ₁, Λ ₂, Λ ₃And Λ ₄Satisfy accurate the condition that is complementary

$\frac{2\mathrm{\π}}{{\mathrm{\λ}}_1}[2n({\mathrm{\λ}}_1/2,T)-2n({\mathrm{\λ}}_1,T)]=\frac{2\mathrm{\π}}{{\mathrm{\Λ}}_1}---\left(1\right)$

$\frac{2\mathrm{\π}}{{\mathrm{\λ}}_2}[2n({\mathrm{\λ}}_2/2,T)-2n({\mathrm{\λ}}_2,T)]=\frac{2\mathrm{\π}}{{\mathrm{\Λ}}_2}---\left(2\right)$

$\frac{2\mathrm{\π}}{{\mathrm{\λ}}_1}[3n({\mathrm{\λ}}_1/3,T)-2n({\mathrm{\λ}}_1/2,T)-n({\mathrm{\λ}}_1,T)]=\frac{2\mathrm{\π}}{{\mathrm{\Λ}}_3}---\left(3\right)$

$\frac{2\mathrm{\π}}{\frac{{\mathrm{\λ}}_1{\mathrm{\λ}}_2}{{\mathrm{\λ}}_1+{\mathrm{\λ}}_2}}[n(\frac{{\mathrm{\λ}}_1{\mathrm{\λ}}_2}{{\mathrm{\λ}}_1+{\mathrm{\λ}}_2},T)-n({\mathrm{\λ}}_1,T)-n({\mathrm{\λ}}_2,T)]=\frac{2\mathrm{\π}}{{\mathrm{\Λ}}_4}---\left(4\right)$

λ wherein ₁, λ ₂Correspond respectively to 1.342 μ m and 1.064 μ m fundamental wave wavelength.The method of the aperiodic structure design that the present invention adopts is included in a kind of specific aperiodic structure by the reciprocal lattice vector of following specific coupling process with multiple periodic structure exactly, and its reciprocal lattice vector height of big maintenance of trying one's best.Its structure function can be expressed as follows:

$G\left(x\right)=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{g}_i\left(x\right)\mathrm{\φ}\left\{\mathrm{floor}\right[\frac{x}{d}-\mathrm{nfloor}\left(\frac{x}{\mathrm{nd}}\right)-i+1\left]\right\}---\left(5\right)$

Wherein, d is the width on minimum farmland, $g_i\left(x\right)=f_i(\frac{\mathrm{floor}\left(\frac{x}{d}\right)+\mathrm{ceil}\left(\frac{x}{d}\right)}{2}\×d),$ And $f_i\left(x\right)=1-2\mathrm{floor}\left(\frac{2x}{{\mathrm{\Λ}}_i}\right)+4\mathrm{floor}\left(\frac{x}{{\mathrm{\Λ}}_i}\right)$ What represent is to be Λ in the cycle _iPeriodic structure, $\mathrm{\φ}\left(x\right)=\left\{\begin{array}{cc}1& \mathrm{ifx}=0\\ 0& \mathrm{else}\end{array},,\right.$ According to desired Λ _i, can design corresponding aperiodic structure, needed a plurality of reciprocal lattice vector is provided.N is the non-linear process number of considering, red, yellow, green, blue four look laser are exported n=4 simultaneously.

Design temperature is 80 ℃; Calculate refractive index according to following dispersion equation;

$n_e(\mathrm{\&lambda;},T)=A+\frac{B+b\left(T\right)}{{\mathrm{\&lambda;}}^2-[C+c\left(T\right){]}^2}+\frac{E}{{\mathrm{\&lambda;}}^2-{\mathrm{<figure-callout\; id="2"\; label="F"\; filenames="C0311284800102.png"\; state="\{\{state\}\}">F</figure-callout>}}^2}+{\mathrm{D\&lambda;}}^2---\left(6\right)$

Parameter wherein

A＝4.5284，B＝7.249×10 ^-3，C＝0.2453，D＝-2.3670×10 ^-2，

E＝7.7690×10 ^-2，F＝0.1838，b(T)＝2.6794×10 ^-8(T+273.15) ²，

c(T)＝1.623×10 ^-8(T+273.15) ²；

Characteristics of the present invention:

1. all solid state laser that multi-wavelength is exported simultaneously in the realization visible light wave range has broad application prospects in fields such as equipment such as the colored demonstration of high-brightness laser, the printing of laser rear-projection laser color and show business.The invention provides the small-sized all solid state laser of realizing that red, yellow, green, blue four look laser are exported simultaneously, have the not available advantage of other laser, the efficient height, simple in structure, easy to use, power output reaches certain level, can improve being applicable to various application occasions.

2. the cavity resonator structure that adopts of the present invention laser generation that can produce 1.064 μ m and 1.342 μ m simultaneously, straight chamber simple in structure is easy to regulate; And the shunt refrative cavity can be regulated the time delay of acoustooptic switch control signal, suppresses the synchronizing characteristics (time-interleaving) that the double wave resonant impulse was competed or improved to double wave.

3.Nd:YVO ₄Crystal has excellent laser activity, and is big as absorption coefficient, absorbs bandwidth, and stimulated emission cross section is big, is output as linear polarization etc.This crystal ⁴F _3/2→ ⁴I _11/2With ⁴F _3/2→ ⁴I _13/2Transition all has bigger emission cross section, and the ratio of their emission cross sections is easy to also realize that dual wavelength vibrates simultaneously, and obtaining efficiently, 1.064 μ m and 1.342 μ m laser export simultaneously.

4. the superlattice structure of the present invention's employing is a kind of specific aperiodic structure.Can be as required, the design corresponding structure provides a plurality of reciprocal lattice vectors effectively, mate a plurality of nonlinear frequency transformation processes simultaneously, and super crystal lattice material and incident first-harmonic are not all had particular restriction, and its structure is easy to obtain and prepare, and has very big flexibility and practicality.

Four, description of drawings

A kind of super crystal lattice full-solid-state red, yellow, green, blue four look laser structure schematic diagrames of Fig. 1 the present invention

Super crystal lattice full-solid-state red, yellow, green, the blue four look laser structure schematic diagrames of Fig. 2 another kind of the present invention

Among Fig. 1

1 semiconductor diode laser (LD), wavelength are 0.808 μ m;

Coupling of 2 optical fiber and collimation focusing system;

3 input mirrors grow tall instead to 1.064 μ m and 1.342 μ m double waves, and are high saturating to 0.808 μ m;

4 Nd:YVO ₄Crystal produces the gain media of 1.064 μ m and 1.342 μ m laser;

5 acousto-optic modulators;

The output cavity mirror of 6 1.342 μ m laser;

The output cavity mirror of 7 1.064 μ m laser;

8 convergent lenses;

9 temperature control furnace are used for regulating temperature;

10 superlattice crystal, frequency translation produces red, yellow, green, blue four look laser.

Among Fig. 2:

1 semiconductor diode laser (LD), wavelength are 0.808 μ m;

Coupling of 2 optical fiber and collimation focusing system;

3 input mirrors grow tall instead to 1.064 μ m and 1.342 μ m double waves, and are high saturating to 0.808 μ m;

4 Nd:YVO ₄Crystal produces the gain media of 1.064 μ m and 1.342 μ m laser;

5 acousto-optic modulators;

The output cavity mirror of 6 1.342 μ m laser;

The output cavity mirror of 7 1.064 μ m laser;

8 convergent lenses;

9 temperature control furnace are used for regulating temperature;

10 superlattice crystal, frequency translation produces red, yellow, green, blue four look laser;

11 45 ° of beam splitters, high saturating to 1.064 μ m on the contrary to 1.342 μ m height;

The high anti-chamber of 12 1.064 μ m mirror;

The high anti-chamber of 13 1.342 μ m mirror.

Five, embodiment

The present invention is described in further detail below in conjunction with accompanying drawing and experimental example.

Embodiment 1 accompanying drawing 1 is to specifications made super crystal lattice full-solid-state red, yellow, green, blue four look lasers (realizing).Pumping source LD output wavelength is 0.808 μ m, and peak power output is 30W.Nd:YVO ₄The crystal 4 front and rear surfaces plates 1.064 and 1.342 μ m antireflective films.3 couples 1.064 μ m of input mirror and 1.342 μ m are all high anti-, form 1.342 μ m laserresonators with chamber mirror 6, form 1.064 μ m laserresonators with chamber mirror 7.Acoustooptic switch 5 places in the chamber, obtains quasi-continuous 1.064 μ m and 1.342 μ m laser.Acyclic polarized LT superlattice 10 (being about 1cm) place temperature control furnace 9, regulate temperature.Output when coupling temperature place can obtain red, yellow, green, blue four look laser.

Embodiment 2

Accompanying drawing 1 is made super crystal lattice full-solid-state red, yellow, green, blue four look lasers to specifications, with different in the example 1 be, all plate with 1.064 μ m and 1.342 μ m antireflective films and visible light antireflective film at superlattice 10 two ends, 3 pairs of visible lights of input mirror are also high anti-, 6 couples 1.342 μ m of output cavity mirror are high to oppose 1.064 μ m and visible light height thoroughly, 7 couples 1.064 μ m of output cavity mirror are high, and the visible light of opposing is high saturating, and superlattice are placed in the chamber, realizes frequency inverted in the chamber.Output when coupling temperature place can obtain red, yellow, green, blue four look laser.

Embodiment 3

Accompanying drawing 2 is made super crystal lattice full-solid-state red, yellow, green, blue four look lasers to specifications.All different with example 1,2 is to have adopted the mode of folding shunt.3 couples 1.064 μ m of input mirror and 1.342 μ m are all high anti-, and 11 is 45 ° of beam splitters, and are high saturating to 1.064 μ m on the contrary to 1.342 μ m height; 12,13 is respectively to 1.064 μ m and the high anti-chamber mirror of 1.342 μ m.1.342 μ m laser vibrates between 13,6,1.064 μ m laser vibrate between 12 and 7.Produce quasi-continuous light by acousto-optic modulator, the time delay that can regulate two-way acousto-optic control signal suppresses the double wave competition or improves the synchronizing characteristics (time-interleaving) that pulsus bisferiens dashes.Outside the chamber, superlattice 10 place temperature control furnace 9, regulate temperature.Output when coupling temperature place can obtain red, yellow, green, blue four look laser.

Embodiment 4

Accompanying drawing 2 is made super crystal lattice full-solid-state red, yellow, green, blue four look lasers to specifications.Different with example 3 is the antireflective film of superlattice two ends plating with 1.064 μ m, 1.342 μ m antireflective films and visible region, require high 1.064 μ m of opposition of 6 couples 1.342 μ m of chamber mirror and visible light high saturating, mirror 7 couples 1.064 μ m in chamber are high, and the visible light of opposing is high saturating, and 12,13 pairs of visible lights are also high anti-.Superlattice place in the chamber, realize frequency inverted in the chamber.Output when coupling temperature place can obtain red, yellow, green, blue four look laser.

Claims (3)

1. the method to set up of super crystal lattice full-solid-state red, yellow, green, blue four look lasers is characterized in that: to mix the Nd ionic crystals is gain media, i.e. Nd:YAG, Nd:YAP or Nd:GdVO ₄, from ⁴F _3/2→ ⁴I _9/2, ⁴I _11/2, ⁴I _13/2, ⁴I _15/2In many spectral lines of energy level transition, select two spectral lines and design the dual wavelength resonant cavity, obtain the dual wavelength first-harmonic and export simultaneously, have aperiodic LT superlattice, select wherein emission mixing the Nd ionic crystals at this dual wavelength first-harmonic design ⁴F _3/2→ ⁴I _11/2Transition spectral line laser realizes that effective frequency multiplication obtains green glow, simultaneously to mixing Nd ionic crystals emission ⁴F _3/2→ ⁴I _13/2Transition spectral line laser is realized frequency multiplication and frequency tripling, obtains ruddiness and blue light, and right ⁴F _3/2→ ⁴I _11/2The transition spectral line and ⁴F _3/2→ ⁴I _13/2Transition spectral line and frequency obtain gold-tinted, output when finishing four look laser.

2. the method to set up of super crystal lattice full-solid-state red, yellow, green, blue four look lasers as claimed in claim 1 is characterized in that: the Nd ionic crystals is mixed in pumping, excites ⁴F _3/2→ ⁴I _11/2With ⁴F _3/2→ ⁴I _13/2Dual wavelength vibrates simultaneously, selects by mixing other spectral line of emission of Nd ionic crystals ⁴F _3/2→ ⁴I _9/2With ⁴F _3/2→ ⁴I _15/2Participate in dual wavelength and vibrate simultaneously, realize a plurality of frequency conversion process simultaneously, export the multi-wavelength visible light simultaneously by superlattice.

3. the method to set up of super crystal lattice full-solid-state red, yellow, green, blue four look lasers as claimed in claim 1 is characterized in that: with the LiTaO of single structure ₃Aperiodic, superlattice were realized the frequency multiplication of 1.064 μ m laser, realized the frequency multiplication and the frequency tripling process of 1.342 μ m laser simultaneously, and 1.064 μ m laser and 1.342 μ m laser and frequently, aperiodic, super crystal lattice material comprised LiTaO ₃, LiNbO ₃, KTP or RTP nonlinear optical material.

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