摘要:
A high power narrow band, high repetition rate laser light source optical improvement apparatus and methods are disclosed with a fast angularly positionable mirror having a mirror mounting frame, a reflective optic with a coefficient different from that of the mounting frame, at least one flexure mount fromed in the mounting frame that is flexible having flexure arm attached the flexture to the mounting frame. The apparatus may include a flexure force mechanism having an elongated rod. The force mechanism may pre-stress the flexure. The mirror maybe a grating which includes a substrate with metallic layer formed on the substrate, and a protective coating made of silica formed on the reflective metallic layer. The grating maybe actively tuned using an electro- or magneto-sensitive element. Oxides of the metal in the reflective layer may be removed by a hydrogen purge system exposed to deep ultraviolet radiation.
摘要:
The present invention provides long life optics for a modular, high repetition rate, ultraviolet gas discharge laser systems producing a high repetition rate high power output beam. The invention includes solutions to a surface damage problem discovered by Applicants on CaF2 optics located in high pulse intensity sections of the output beam of prototype laser systems. Embodiments include an enclosed and purged beam path with beam pointing control for beam delivery of billions of output laser pulses. Optical components and modules described herein are capable of controlling ultraviolet laser output pulses with wavelength less than 200 nm with average output pulse intensities greater than 1.75×106 Watts/cm2 and with peak intensity or greater 3.5×106 Watts/cm2 for many billions of pulses as compared to prior art components and modules which failed after only a few minutes in these pulse intensities. Techniques and components are disclosed for minimizing the potential for optical damage and for reducing the pulse energy density to less than 100×10−6 J/cm3. Important improvements described in this specification have been grouped into the following subject matter categories: (1) Solution to CaF2 surface damage discovered by Applicants, (2) description of a high power ArF MOPA laser system, (3) description of beam delivery units, (4) polarization considerations (5) a high speed water-cooled auto shutter energy detector module and (6) other improvements.
摘要翻译:本发明提供了用于产生高重复率高功率输出光束的模块化高重复率紫外线气体放电激光器系统的长寿命光学器件。 本发明包括由申请人发现的位于原型激光系统的输出光束的高脉冲强度部分中的CaF 2光学器件的表面损伤问题的解决方案。 实施例包括用于束传送数十亿个输出激光脉冲的光束指向控制的封闭和清除的光束路径。 本文所述的光学部件和模块能够控制波长小于200nm的紫外激光输出脉冲,平均输出脉冲强度大于1.75×6 /瓦/ cm 2,并且与 与在这些脉冲强度中仅仅几分钟之后失效的现有技术部件和模块相比,数十亿个脉冲的峰值强度或更大的3.5×10 6 / cm 2 / SUP。 公开了用于最小化光学损伤的可能性和将脉冲能量密度降低到小于100×10 -6 / cm 3的技术和部件。 本说明书中描述的重要改进已分为以下主题类别:(1)由申请人发现的CaF 2 2表面损伤的解决方案,(2)高功率ArF MOPA激光系统的描述( 3)光束传输单元的描述,(4)偏振考虑(5)高速水冷自动快门能量检测器模块和(6)其他改进。
摘要:
The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses at 2000 Hz with a full width half, maximum bandwidth of about 0.6 pm or less. Replaceable modules include a laser chamber; a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module and an output coupler module; a wavemeter module, an electrical control module, a cooling water module and a gas control module. Improvements in the laser chamber permitting the higher pulse rates and improved bandwidth performance include a single upstream preionizer tube and a high efficiency chamber. The chamber is designed for operation at lower fluorine concentration. Important improvements have been provided in the pulse power unit to produce faster rise time and improved pulse energy control. These improvements include an increased capacity high voltage power supply with a voltage bleed-down circuit for precise voltage trimming, an improved commutation module that generates a high voltage pulse from the capacitors charged by the high voltage power supply and amplifies the pulse voltage 23 times with a very fast voltage transformer having a secondary winding consisting of a single four-segment stainless steel rod. A novel design for the compression head saturable inductor greatly reduces the quantity of transformer oil required and virtually eliminates the possibility of oil leakage which in the past has posed a hazard.
摘要:
A gas discharge laser with fast response gas temperature control to maintain laser gas temperature within desired limits during burst mode operation. Preferred embodiments include a passive temperature stabilizer having fins with surface areas exposed to flowing laser gas at least equal to the surface area of the cooling fins of a laser gas heat exchanger. Preferred embodiments utilize heating elements and coolant flow control to regulate laser gas temperatures using processors programmed to anticipate idle periods.
摘要:
The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses in the range of 1000 Hz to 2000 Hz with a full width half, maximum bandwidth of about 0.6 pm or less. Replaceable modules include a laser chamber, a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module and an output coupler module; a wavemeter module, an electrical control module, a cooling water module and a gas control module. Important improvements have been provided in the pulse power unit to produce faster rise time and improved pulse energy control. These improvements include an increased capacity high voltage power supply with a voltage bleed-down circuit for precise voltage trimming, an improved commutation module that generates a high voltage pulse from the capacitors charged by the high voltage power supply and amplifies the pulse voltage 23 times with a very fast voltage transformer having a secondary winding consisting of a single four-segment stainless steel rod. A novel design for the compression head saturable inductor greatly reduces the quantity of transformer oil required and virtually eliminates the possibility of oil leakage which in the past has posed a hazard.
摘要:
The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses in the range of 1000 Hz to 2000 Hz or greater. Replaceable modules include a laser chamber; a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module and an output coupler module; a wavemeter module, an electrical control module, a cooling water module and a gas control module. Important improvements have been provided in the pulse power unit to produce faster rise time and improved pulse energy control. These improvements include an increased capacity high voltage power supply with a voltage bleed-down circuit for precise voltage trimming, an improved commutation module that generates a high voltage pulse from the capacitors charged by the high voltage power supply and amplifies the pulse voltage 23 times with a very fast voltage transformer having a secondary winding consisting of a single four-segment stainless steel rod. A novel design for the compression head saturable inductor greatly reduces the quantity of transformer oil required and virtually eliminates the possibility of oil leakage which in the past has posed a hazard.
摘要:
The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses in the range of 1000 Hz to 2000 Hz or greater. Replaceable modules include a laser chamber; a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module and an output coupler module; a wavemeter module, an electrical control module, a cooling water module and a gas control module. Important improvements have been provided in the pulse power unit to produce faster rise time and improved pulse energy control. These improvements include an increased capacity high voltage power supply with a voltage bleed-down circuit for precise voltage trimming, an improved communication module that generates a high voltage pulse from the capacitors charged by the high voltage power supply and amplifies the pulse voltage 23 times with a very fast voltage transformer having a secondary winding consisting of a single four-segment stainless steel rod. A novel design for the compression head saturable inductor greatly reduces the quantity of transformer oil required and virtually eliminates the possibility of oil leakage which in the past has posed a hazard.
摘要:
The present invention provides a process for substantially extending the useful life of fused silica elements used in high energy ultraviolet optical systems. The fused silica bulk material is pre-compacted by illuminating it with radiation prior to final mechanical fabrication and polishing to the required final surface figure. When the optical element is subsequently used in a high energy ultraviolet environment, it will continue to be compacted but at a lower effective rate. As a result, the useful life of fused silica optical elements can be increased substantially.In preferred embodiments the fused silica material is precompacted with multiple passes of short-pulse ultraviolet radiation. Multiple passes can reduce precompaction time. In one example useful life of the fused silica is increased from about 150 days to 3.8 years by about 5 days of precompaction.
摘要:
Methods and apparatus are provided for cleaning and passivating laser discharge chambers with plasmas. In one embodiment, an oxygen based plasma is formed in a plasma source external to the laser discharge chamber by applying a radiofrequency signal to oxygen containing gases. The oxygen based plasma is drawn into the laser discharge chamber, where it reacts with contaminants and cleans internal surfaces. After cleaning, a fluorine based plasma is formed in the plasma source and drawn into the laser discharge chamber to passivate internal surfaces. In another embodiment, cleaning with the oxygen based plasma is not used since some level of cleaning is accomplished with the fluorine based plasma. In another embodiment, oxygen based plasmas and fluorine based plasmas are formed in the laser discharge chamber by applying a radiofrequency signal to a laser discharge chamber electrode. Plasma cleaning and passivation of laser discharge chambers is safer, more efficient, and more effective than conventional thermal cleaning and passivation processes.
摘要:
Methods and apparatus are provided for cleaning and passivating laser discharge chambers with plasmas. In one embodiment, an oxygen based plasma is formed in a plasma source external to the laser discharge chamber by applying a radiofrequency signal to oxygen containing gases. The oxygen based plasma is drawn into the laser discharge chamber, where it reacts with contaminants and cleans internal surfaces. After cleaning, a fluorine based plasma is formed in the plasma source and drawn into the laser discharge chamber to passivate internal surfaces. In another embodiment, cleaning with the oxygen based plasma is not used since some level of cleaning is accomplished with the fluorine based plasma. In another embodiment, oxygen based plasmas and fluorine based plasmas are formed in the laser discharge chamber by applying a radiofrequency signal to a laser discharge chamber electrode. Plasma cleaning and passivation of laser discharge chambers is safer, more efficient, and more effective than conventional thermal cleaning and passivation processes.