JP2000101175A - Solid-state passive q-switch block, solid-state q-switch laser oscillator, and solid-state laser device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a reliable solid-state passive Q-switch laser device by constituting it with a solid passive switch block, without breakdowns due to heat being generated by a solid-state passive Q-switch. SOLUTION: A switch block is constituted of a solid-state passive Q-switch 1 and the end faces of crystals 2 (2a and 2b) that are transparent to a laser beam which is optically and physically connected to at least one end face of the solid-state passive Q-switch 1. In this case, materials with nearly equal coefficient of linear expansion and the refractive index of the solid-state passive Q-switch block 1 are used as the transparent crystal 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a configuration of a solid-state passive Q switch block, a solid-state Q-switched laser oscillator using the solid-state passive Q-switch block, and a configuration of a solid-state laser device.

[0002]

2. Description of the Related Art FIG. 10 shows a solid passive Q switch block disclosed in Japanese Patent Application Laid-Open No. 9-29833. 1 in the figure
Is a solid passive Q switch, 2a and 2b are in contact with the end face of the solid passive Q switch 1, a crystal transparent to laser light, and 100 is an optical axis. FIG. 11 shows the transmittance characteristics of the solid passive Q switch. FIG. 12 shows a direction in which heat generated by the solid passive Q switch 1 moves to the crystal 2 which is transparent to laser light. In FIG. 12, reference numeral 200 indicates the direction of heat transfer.

[0003] The solid passive Q switch 1 is one in which ions having a property of absorbing laser light are added to a solid crystal called a host crystal.

Next, the operation will be described. The solid-state passive Q switch 1 has a transmittance characteristic as shown in FIG. 11, and when the energy density of the laser light is low immediately after the start of excitation of the laser medium, the laser light is almost absorbed by the passive Q switch and the transmittance is reduced. Low, lossy Q-switch closed. As time elapses from the start of excitation of the laser medium, the energy density of the laser light increases, and with this increase, the proportion of the laser light absorbed in the solid passive Q switch 1 decreases, the transmittance increases, and the solid The loss of the passive Q switch decreases. When the gain of the laser medium finally matches the sum of the resonator loss and the loss of the solid passive Q switch 1, the solid passive Q switch 1 is in an open state, and Q switch oscillation occurs.

The energy required until the solid passive Q switch 1 is changed from closed to open is obtained by the solid passive Q switch 1 absorbing laser light. Almost all the energy of the absorbed laser light is converted to heat.
The heat generated by the solid passive Q switch 1 is converted into a transparent crystal 2a.
And 2b.

The amount of heat generated by the solid passive Q switch 1 depends on the amount of laser light absorbed by the solid passive Q switch 1.
It has a distribution in the radial direction on a plane perpendicular to the optical axis direction of the laser light. For this reason, the solid passive Q switch 1 has a temperature distribution in the radial direction of a plane perpendicular to the optical axis direction of the laser light.

The flow of heat generated by the solid passive Q switch 1 to the transparent crystals 2a and 2b is shown in FIG.
Since they are parallel to the optical axis direction of the laser as in a, 200b, 200c, and 200d, no temperature distribution occurs in the radial direction on a plane perpendicular to the optical axis direction due to the movement of heat.

The solid passive Q switch 1 is configured as described above, and can reduce the temperature distribution in the radial direction on a plane perpendicular to the optical axis direction.
There is an advantage that the thermal lens effect and the thermal birefringence effect of the switch 1 can be reduced, and the output of laser light and the beam quality of laser light can be improved.

FIG. 13 shows a solid passive Q switch block disclosed in Japanese Patent Application Laid-Open No. 1-248584. In the figure, 300 is a saturable absorber plastic film which is a saturable absorber, 400a and 400b are thermally conductive transparent members such as sapphire and diamond plates, and the saturable absorber 300 is sandwiched between the thermally conductive transparent members 400a and 400b. ing.

For this reason, the heat generated in the saturable absorber 300 before the Q switch is opened is transferred to the thermally conductive transparent body 400a,
It is quickly discharged outside through 400b. For this reason, the temperature rise of the saturable absorber 300 can be prevented,
The number of laser repetitions can be increased.

[0011]

Since the conventional solid-state passive Q-switch is configured as described above, when the laser output increases or the number of laser repetitions increases, the heat generated by the solid-state passive Q-switch 1 increases. As the amount increases, the temperature rise of the host crystal and the transparent crystal 2 of the solid passive Q switch 1 increases. It is desirable that the temperature of the solid passive Q switch 1 be low in order to suppress the change in the optical characteristics of the solid passive Q switch 1 itself. Crystals with high conductivity were used. As a combination thereof, Cr4 +: YAG (refractive index: 1.8) is used as the solid passive Q switch 1.
9, linear expansion coefficient: 7.7 × 10 −6 / K, thermal conductivity: 1
3.6 W / m · K), sap as conventional transparent crystal 2
phire (refractive index: 1.77, linear expansion coefficient: 6.7 × 1)
0-6 / K, thermal conductivity: 46 W / m · K). At this time, since the linear expansion coefficients of the two are different, a stress is generated between the solid passive Q switch 1 and the crystal 2 transparent to the laser beam due to a difference in the linear expansion amount due to a temperature rise, and the solid Q switch block is broken. Thus, there is a problem that the Q switch operation of the laser device stops.

In order to prevent the destruction due to the stress, at the expense of a temperature rise in the solid passive Q switch block, CaMoO4 (refractive index: 1. 95, coefficient of linear expansion: 7.6 × 10 −6 / K, thermal conductivity: 4.0 W / m ·
Even if K) is adopted as the transparent crystal 2, the host crystal of the solid passive Q switch 1 and the transparent crystal 2 have different refractive indices, so that Fresnel reflection occurs at the contact surface between the solid passive Q switch 1 and the transparent crystal 2. Occurs, and the resonator loss increases, which causes a problem that the laser output decreases.

As described above, as the host crystal and the transparent crystal 2 of the solid-state passive Q switch 1, it is necessary to combine crystals having substantially the same linear expansion coefficient and substantially the same refractive index. An object is to provide a transparent crystal 2 that solves the problem.

[0014]

According to a first aspect of the present invention, there is provided a solid-state passive Q switch block comprising: a solid-state passive Q switch;
In the solid passive Q switch block including a heat radiator transparent to the physically connected laser light, the transparent heat radiator has a linear expansion coefficient and a refractive index substantially equal to those of the host crystal of the solid passive Q switch. The same material was used.

The solid passive Q switch block according to the second invention uses the same crystal as the host crystal and the transparent crystal of the solid passive Q switch of the first invention.

According to a third aspect of the present invention, in the solid passive Q switch block according to the first or second aspect, optical and physical connection with the transparent heat radiator is performed by optical bonding.

According to a fourth aspect of the present invention, there is provided a solid passive Q switch block according to the first or second aspect, wherein the optical and physical connection with the transparent radiator is made by thermal bonding.

According to a fifth aspect of the present invention, there is provided the solid-state passive Q switch block according to any one of the first to fourth aspects, wherein the transparent heat radiation on the side not optically and physically connected to the solid-state passive Q switch. A lateral single mode forming mechanism is formed on the end face of the body.

A solid passive Q-switch block according to a sixth aspect of the present invention is the solid-state passive Q-switch block according to the fifth aspect, wherein a mode selection aperture is formed as the lateral single mode mechanism.

The solid passive Q switch block according to the seventh invention is the solid passive Q switch according to any one of the first invention to the fourth invention, wherein the solid passive Q switch is Cr4 +: GSGG.
Using GSGG as a crystal transparent to laser light.

According to an eighth aspect of the present invention, there is provided the solid-state passive Q switch block according to any one of the first to fourth aspects, wherein the solid passive Q switch is U2 +: CaF2.
Using CaF2 as a crystal transparent to a laser beam.

The solid passive Q switch block according to the ninth invention is the solid passive Q switch according to any one of the first invention to the fourth invention, wherein Er3 +: CaF2 is used as the solid passive Q switch.
Using CaF2 as a crystal transparent to a laser beam.

According to a tenth aspect of the present invention, there is provided a solid-state passive Q-switched laser oscillator comprising: a pair of total reflection mirrors and an output mirror constituting a resonator; a solid-state laser medium disposed in the resonator; And a solid-state Q-switched laser oscillator comprising a solid-state Q-switch block according to any one of the first to sixth aspects disposed in the resonator, wherein the solid-state laser and the solid-state passive Q-switch are provided. The solid passive Q switch of the block uses a material having the opposite sign of the focal length of the thermal lens.

An eleventh aspect of the present invention is the solid-state passive Q-switch laser oscillator according to the tenth aspect, wherein the solid-state laser medium is Yb: YAG and the solid-state passive Q-switch is U2: YAG.
+: CaF2 was used.

According to a twelfth aspect of the present invention, there is provided a solid-state passive Q-switched laser device according to the tenth or eleventh aspect, wherein the saturable absorber provided on the optical axis in the laser light emission direction in the Q-switched laser oscillator. It is provided with.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 shows a first embodiment of the present invention. In the figure, 1 is a solid passive Q
The switches, 2a and 2b, are the same host crystals as the solid-state passive Q switch and are transparent to laser light, 3 is the solid-state passive Q switch block, and 100 is the optical axis. FIG. 2 shows the flow of heat in the solid passive Q switch block 3.

Next, the operation will be described. Since the solid passive Q switch 1 has a transmittance characteristic as shown in FIG.
In a state where the energy density of the laser light is low immediately after the start of the laser excitation, the laser light is almost absorbed by the solid-state passive Q switch 1, and the Q switch is in a closed state where the transmittance is low and the loss is high. As time elapses from the start of laser excitation, the energy density of the laser light increases, and with this increase, the proportion of the laser light absorbed in the solid-state passive Q switch 1 decreases, the transmittance increases, and the loss decreases. I will do it. When the gain of the laser finally matches the sum of the loss of the resonator and the loss of the solid-state passive Q switch 1, the solid-state passive Q switch 1 is opened, and Q-switch oscillation occurs.

The energy required until the solid passive Q switch 1 changes from closed to open is obtained by the solid passive Q switch 1 absorbing laser light. Almost all the energy of the absorbed laser light is converted to heat.
At this time, the heat generated by the solid passive Q switch 1 is as shown in FIG.
Move in the direction parallel to the optical axis 100 as shown in FIGS. 200a, 200b, 200c, and 200d, and move to the transparent crystals 2a and 2b.

Since the amount of heat generated by the solid-state passive Q switch 1 depends on the amount of laser light absorbed by the solid-state passive Q switch 1, the amount of heat generated in the radial direction of the plane perpendicular to the optical axis direction of the laser light is changed. Has a distribution. For this reason, it has a temperature distribution in the radial direction of the plane perpendicular to the optical axis direction of the laser light.

However, since the solid passive Q switch 1 and the crystal 2 that is transparent to laser light are the same host crystal, even if a temperature distribution occurs, the generation of shear stress caused by the difference in the coefficient of linear expansion between them will not occur. No, passive solid Q by temperature distribution
The switch block is not destroyed.

Further, in this solid passive Q switch block, the temperature distribution in the radial direction on a plane perpendicular to the optical axis direction can be reduced. There is an advantage that the thermal birefringence effect is reduced, and the output of laser light and the beam quality of laser light can be improved.

Further, in this solid passive Q switch block, since the refractive index of the host crystal and the transparent crystal 2 of the solid passive Q switch 1 are the same, Fresnel reflection does not occur and the laser output does not decrease. .

As means for optically and physically connecting the solid passive Q switch 1 and the transparent crystals 2a and 2b,
There is a method of so-called optical bonding, in which an end face where the solid passive Q switch 1 and the transparent crystal 2 are connected is optically polished, and then the end faces are brought into close contact with each other, and pressure is applied to the contact face to adhere.

According to this bonding method, an optical adhesive is not required, and there is an advantage that a highly reliable solid-state passive Q-switch having no change in optical characteristics of the optical adhesive due to absorption of laser light can be formed.

Also, a crystal 2a which is a solid passive Q switch 1
Solid and passive Q as optical and physical connection methods of
A method of optically polishing the end face where the switch 1 and the transparent crystal 2 are connected and then bringing the end faces into close contact with each other and applying pressure and temperature to the contact face, so-called heat bonding or US Oni.
x diffusion bonding (diffusion)
bonding).

According to this bonding method, there is an advantage that an optical adhesive is not required, and a highly reliable solid-state passive Q-switch having no change in optical characteristics of the optical adhesive due to absorption of laser light can be formed. Further, this bonding method allows bonding after applying an anti-reflection coating to the end faces of the solid passive Q switch 1 and the transparent crystal 2, so that the loss of the laser oscillator can be reduced and the laser output can be improved. is there.

As a combination of the solid passive Q switch 1 and the crystal 2 transparent to the laser beam, Cr4 +: GSGG ( Linear expansion coefficient: 1
0.5 × 10 −6 / K, refractive index: 1.94) and GSGG (linear expansion coefficient: 10.5 × 10 −6 /
K, refractive index: 1.94), the emission laser wavelength is 0.98 μm.
For Yb: laser in the m band, U2 +: CaF2 (linear expansion coefficient: 18.9 × 1)
0-6 / K, refractive index: 1.43) and CaF2 (linear expansion coefficient: 18.9 × 10-6 / K, refractive index: 1.43) as a transparent crystal 2 at an emission laser wavelength of 1.5 μm band. For a certain Er: laser, Er3 +: CaF2 (linear expansion coefficient: 18.9 × 10 −6 /
K, refractive index: 1.43) and CaF2 as transparent crystal 2
(Linear expansion coefficient: 18.9 × 10 −6 / K, refractive index: 1.4)
3) is conceivable.

Embodiment 2 FIG. 3 shows a method of manufacturing a solid passive Q switch block according to the present invention. In the figure, 50a is a solid passive Q switch block, and 55 is a cutting line.

The manufacturing method will be described. After optically and physically adhering the optical components constituting the solid passive Q switch block 3, the cutting lines 55a and 55b are used to form a plurality of solid passive Q switches 50a using a dicing saw or the like. Disconnect.

By using the above-described manufacturing method, a plurality of solid passive Q switch blocks 50a can be manufactured simultaneously in one expensive process such as polishing of the solid passive Q switch 1 and the crystal 2, so that the cost can be reduced. Also, there is an advantage that the individual variation is small and the yield is increased.

Embodiment 3 FIG. 4 shows a third embodiment of the present invention. In the figure, 20 is a total reflection mirror,
30 is an output mirror, 40 is a solid-state laser medium Yb: YA
G and 50 are solid passive Q switch blocks using U ²⁺ : CaF2 as solid passive Q switches, and 60 is an excitation light source for exciting a solid laser medium. FIG. 5 shows the laser output power dependence of the focal length of the thermal lens.

Next, the operation will be described. As shown in FIG. 5, the signs of the thermal lens focal lengths of Yb: YAG and U ²⁺ : CaF2 are different. For this reason, as the laser medium 50, Y
When b: YAG is used and U ²⁺ : CaF 2 is used as the solid passive Q switch of the solid passive Q switch block, the thermal lens focal length of the entire laser oscillator becomes U ²⁺ : CaF 2 alone and Yb: The size can be reduced as compared with the case of YAG alone.

With the above configuration, a laser oscillator can be configured by reducing the total thermal lens focusing effect in the resonator, and the output of the laser oscillator and the beam quality can be improved.

This effect is obtained because the laser medium is Yb: YA
G, the solid passive Q switch medium is not limited to the combination of U ²⁺ : CaF2, and there is no problem if the laser medium and the solid passive Q switch have different signs of the focal length of the thermal lens.

Embodiment 4 In the laser oscillator which is not in the transverse single mode at the time of normal oscillation, a Q-switch is provided by using the solid-state passive Q-switch block 65 of the present invention.
When a laser device is manufactured, a plurality of transverse modes oscillate, so that the Q-switch oscillation pulse is a pulse train composed of a large number of pulses with a pulse interval of several tens to several hundreds of ns.

Therefore, in order to make the Q-switch output one or two pulses, the laser oscillator may be set to the transverse single mode.

FIG. 6 shows a fourth embodiment of the present invention. In the drawing, a solid passive Q switch 1 and transparent crystals 2a and 2b are the same as those in the first embodiment, and 6 is a transparent crystal provided with an opening for making the transverse mode of the laser beam into a single mode.

The operation will be described. Since the solid passive Q switch 1 has the transmittance characteristic as shown in FIG. 11, the laser light is almost absorbed by the passive Q switch when the energy density of the laser light is low immediately after the start of laser excitation.
Low transmission, high loss Q-switch closed. As time elapses from the start of laser excitation, the energy density of the laser light increases, and with this increase, the proportion of the laser light absorbed in the solid-state passive Q switch 1 decreases, the transmittance increases, and the loss decreases. I will do it. When the gain of the laser finally matches the sum of the resonator loss and the loss of the solid-state passive Q switch 1, the solid-state passive Q switch 1 is in an open state, and Q-switch oscillation occurs.

The energy required until the solid passive Q switch 1 is changed from closed to open is obtained by the solid passive Q switch 1 absorbing the laser light, but almost all the energy of the absorbed laser light is converted into heat. Is done. The heat generated in the solid passive Q switch 1 moves to the transparent crystals 2a and 2b.

The amount of heat generated by the solid passive Q switch 1 depends on the amount of laser light absorbed by the solid passive Q switch 1.
It has a distribution in the radial direction on a plane perpendicular to the optical axis direction of the laser light. Therefore, although it has a temperature distribution in the radial direction of the plane perpendicular to the optical axis direction of the laser light, since the solid passive Q switch 1 and the crystal transparent to the laser light are the same host crystal, No breakage due to shear stress due to difference in linear expansion coefficient.

Further, since the transparent crystal 6 provided with the aperture for selecting the transverse mode is joined to the transparent crystal 2, oscillation in only the transverse fundamental mode can be obtained. Therefore, it is possible to prevent the Q switch pulse from becoming a pulse train composed of a large number of pulses at intervals of several tens to several hundreds of ns.

In FIG. 6, an opening for mode selection is provided for single transverse mode selection, but another single transverse mode conversion mechanism may be provided. For example, a mirror whose transmittance changes in accordance with the distance in the radial direction depending on the radial direction is used as a transparent crystal 2.
The method of forming on may be sufficient.

The solid passive Q switch block 6 of the present invention
In the laser device using No. 5, the Q-switch oscillation pulse as shown in FIG. 7 is a pulse train oscillation composed of two pulses having a pulse interval of several tens ns or less. In this pulse train,
The output of the first pulse is several to several tens times larger than the output of the second pulse.

Embodiment 5 FIG. FIG. 8 shows a fifth embodiment of the present invention. In the figure, 20 is a total reflection mirror, 30 is an output mirror, 40 is a laser medium, 50 is a solid passive Q switch block, 70 is a saturable absorber, and 120 is a Q switch laser device. Here, a solid passive Q switch having an initial transmittance smaller than that of the solid passive Q switch block 50 is used as the saturable absorber 70.

The output time waveform of the Q-switch laser of the Q-switch laser device 120 is as shown in FIG. The transmittance characteristic of the saturable absorber 70 is set so that the second pulse shown in FIG. 6 does not pass but the first pulse does.

Next, the operation will be described. The Q switch pulse emitted from the Q switch laser device 120 enters the saturable absorber 70. The first Q switch pulse passes through the saturable absorber 70 with little absorption by the saturable absorber, but the second Q switch pulse is absorbed by the saturable absorber and cannot pass through the saturable absorber 70. For this reason,
Only the first pulse passes through the saturable absorber 70, and the laser output is a single pulse.

According to this embodiment, a single-pulse Q-switched pulse laser oscillator can be configured with a small number of optical components. Further, since the solid passive Q switch block 50 of the present invention is used, the radial temperature distribution on a plane perpendicular to the optical axis direction can be reduced, and the solid passive Q switch 1 in the solid passive Q switch 1 can be reduced by the temperature distribution. There is also an advantage that the thermal lens effect and the thermal birefringence effect can be reduced, and the output of laser light and the beam quality of laser light can be improved.

[0058]

According to the first to ninth aspects, the shear stress due to the temperature distribution to the solid passive Q switch and the laser beam can be reduced, and the solid passive Q switch block is prevented from being broken.

According to the tenth or eleventh aspect, the focal length of the thermal lens in the laser resonator can be reduced.
The output of the laser oscillator can be improved and the beam quality can be improved.

Further, according to the twelfth aspect, there is an effect that a single pulse output laser output can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a solid-state passive Q switch block according to Embodiment 1 of the present invention.

FIG. 2 illustrates heat transfer in the solid passive Q-switch block of FIG.

FIG. 3 shows a method of manufacturing the solid-state passive Q switch block in FIG. 1;

FIG. 4 is a configuration diagram of a laser oscillator using a solid-state passive Q switch block according to Embodiment 3 of the present invention.

FIG. 5 is a laser output dependency of the thermal lens focal length of Yb: YAG and U ²⁺ : CaF2.

FIG. 6 is a configuration diagram of a solid-state passive Q-switch block that performs horizontal single mode according to a fourth embodiment of the present invention.

FIG. 7 is a time waveform of a Q-switch output in the laser device of FIG. 6;

FIG. 8 is a configuration diagram of a laser device using a solid-state passive Q switch block according to Embodiment 5 of the present invention.

FIG. 9 is a time waveform of a Q-switch output in the laser device of FIG. 8;

FIG. 10 shows a conventional example.

FIG. 11 is an example of a transmittance characteristic with respect to input energy of a solid-state passive Q switch.

FIG. 12 shows a flow of heat generated by a solid passive Q switch.

FIG. 13 is a diagram showing a conventional example.

[Explanation of symbols]

1 solid passive Q switch, 2 transparent crystal, 3 solid passive Q switch block, 5 solid passive Q switch block, 6 transparent crystal, 7 solid Q switch block, 2
0 total reflection mirror, 30 output mirror, 40 laser medium, 50
Solid passive Q switch block, 60 excitation light source, 70
Saturable absorber, 100 optical axis, 120 laser oscillator,
200 Heat transfer direction, 300 Supersaturated absorber plastic film, 400 Thermally conductive transparent body.

Claims (12)

[Claims] 1. A solid state passive Q switch and said solid state passive Q switch
A solid passive Q switch block comprising: a heat radiator that is optically and physically connected to at least one end face of the switch; and that is transparent to laser light. As the transparent heat radiator, a host of the solid passive Q switch A solid-state passive Q-switch block using a material having substantially the same linear expansion coefficient and refractive index as a crystal. 2. The passive Q switch block according to claim 1, wherein the same crystal is used as a host crystal of the solid passive Q switch and the transparent radiator. 3. The solid passive Q according to claim 1, wherein optical connection between said solid passive Q switch and said transparent radiator is performed by optical bonding.
Switch block. 4. The solid passive Q switch block according to claim 1, wherein an optical and physical connection between the solid passive Q switch and the transparent radiator is made by thermal bonding. 5. A single transverse mode conversion mechanism is formed on an end face of the transparent heat radiator on a side not optically and physically connected to the solid passive Q switch. 5. The solid-state passive Q switch block according to any one of 4. 6. The solid passive Q switch block according to claim 5, wherein a mode selection aperture is formed as the lateral single mode mechanism. 7. A solid-state passive Q switch comprising Cr4
The solid passive Q switch block according to any one of claims 1 to 4, wherein GSGG is used as a crystal transparent to laser light. 8. The solid-state passive Q-switch as U2 +:
The solid passive Q switch block according to any one of claims 1 to 4, wherein CaF2 is used as a crystal transparent to laser light. 9. An Er3 solid-state passive Q switch.
The solid passive Q switch block according to any one of claims 1 to 4, wherein +: CaF2 is used as a crystal transparent to laser light. 10. A pair of total reflection mirrors and an output mirror constituting a resonator, a solid-state laser medium disposed in the resonator, means for exciting the solid-state laser medium, and disposed in the resonator. A solid-state Q-switched laser oscillator comprising the solid-state passive Q-switch block according to any one of claims 1 to 6, wherein the solid-state laser medium and the solid-state passive Q-switch of the solid-state passive Q-switch block are provided with heat. A solid-state Q-switched laser oscillator characterized by using a material having the opposite sign of the lens focal length. 11. The solid-state laser medium includes Yb: YAG,
The solid-state Q-switched laser oscillator according to claim 10, wherein U2 +: CaF2 is used for the solid-state passive Q-switch. 12. A solid-state laser device according to claim 10, further comprising a saturable absorber on an optical axis in a laser light emitting direction in the solid-state Q-switched laser oscillator according to claim 10.