January 16, 2007
Laserfront Technologies, Inc. |
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Development of the world’s most powerful 100W output
high class all solid-state ultraviolet laser |
Laserfront Technologies, Inc. (in Kanagawa, Japan referred to below as LFT), has achieved the worlds first Nd:YAG laser (Ref# 1) using THG (wavelength 355nm: Ref#2) to produce an output which exceeds 100W (maximum output of 125W, high repetition of 10kHz and a high pulse stability of 1.4%σ). With this new technological advancement LFT has started production of THG Nd: YAG lasers with a high output level of 50W, and from today (Jan. 16, 2007) commences sales of these under the title ‘SL188AT Oscillator’. Also, LFT plans to have an exhibition panel at Internepcon Japan being held from January 17.
Until now, in the field of ultraviolet, only the Excimer laser (Ref# 4) was able to exceed an output level of 100W. However, generally the Excimer had high costs due to its medium gas and to the replacement of its electrode. Furthermore, the operating frequency was of a degree several hundred Hz lower. On the other hand, in regards to Nd:YAG lasers (wavelength 1,064nm), high output lasers even though already commercialized with output levels exceeding 10kW, in the field of ultraviolet light (THG: wavelength 355nm) had problems with both the durability and the efficiency of optic elements used in the wavelength conversion. And, it was advertised that by way of experiment 80W were exceeded, but product wise these were in fact limited to only a level of 10-20W. Because of this, the application of both in the production line was limited to this alone.
The development this time was realized through the optimization and refinement of LFT’s original internal resonator frequency conversion system (COSMIC method: Ref#3) employed in the high output ultraviolet laser (high class 50W output, January, 2006) mentioned in the previous publication. LFT’s new method, compared with conventional methods provides a high stability with high output and a system structure with excellent cost performance. Furthermore, it is expected that it will be applied in not only the development of cutting, script for the processing of punching, and scribing of high transparent molecular material, glass, and semiconductors made from Si, sapphire and GaN, but also be applied in new processing fields that are yet to be discovered.
The main characteristics of the new high output ultraviolet laser are outlined below.
[1] The high output laser is due to LFT’s original internal resonator frequency conversion system. By applying a complex resonator method, LFT’s original internal resonator frequency transformation system (COSMIC method: Ref#3) made it possible to achieve the THG 125W output.
[2] It is possible to have a rapid stable laser processing system where a high repetition of 10kHz can be achieved while at the same time maintaining a stable output level below σ=2%, due to the original internal resonator frequency conversion system. |
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Ref. #1: YAG Solid-State Laser
YAG Solid-State Laser: YAG is the representative laser medium of solid-state lasers, and is the abbreviated form of Yttrium Aluminum Garnet. It is used as the laser crystal of solid-state lasers, has excellent stability and durability and has become a synonym for solid-state lasers. Within this sphere, the laser of an emitted wavelength 1.06 μm of ion doped Nd:YAG is widely used in processing system applications. From this wavelength with the application of wavelength conversion, Third Harmonic Generation (THG), ultraviolet light (355nm) can be generated.
Ref. #2: THG
THG: THG is the abbreviation form of Third Harmonic Generation and is the third harmonic. A main example of this is the production of a summed frequency ultraviolet light (355nm) through conversion by way of incidence of both the fundamental (1.06 μm) and SHG (532nm) of a YAG laser with a non-linear optic crystal.
Ref. #3: Structure of internal resonator frequency
Structure of internal resonator frequency: In this structure the laser resonator wavelength converting element is set inside the laser resonator. In comparison with a structure where the laser resonator wavelength converting element is set on the outside, with the resonator set on the inside the fundamental can be trapped and the frequency is transformed in a state of high power, thus a high conversion efficiency can be achieved. LFT’s COSMIC (Confocal-setting for Stable Mode Intra Cavity) method features a structure that incorporates into a conventional internal resonator frequency conversion structure an enhanced ability to get an optimum power density upon frequency conversion elements. (In application for a patent)
Ref. #4: The Excimer laser
The Excimer laser: uses a mixed gas of both rare gas and halogen gas, and when used with a pulse discharge a UV laser light can be generated. The XeCl Laser (wavelength 308nm) is the representative laser that can exceed a 100W high output ultraviolet laser source. |
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| Specifications for the high output ultraviolet laser |
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| Repetition |
SL188AT
(commencing sales) |
SL188AT2
(in development) |
| Laser medium |
Nd:YAG |
| Emitted wavelength |
355nm |
| Maximum output |
50W |
100W |
| Repetition rate |
5 - 15kHz |
| Pulse width |
- 100ns |
| Polarization |
Linear polarization (horizontal direction) |
| Pumping source |
LD Pumping |
| Power supply |
φ 3-200V 30A |
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