Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
  • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
  • H01S3/02—Constructional details
  • H01S3/04—Arrangements for thermal management
• • G—PHYSICS
  • G12—INSTRUMENT DETAILS
  • G12B—CONSTRUCTIONAL DETAILS OF INSTRUMENTS, OR COMPARABLE DETAILS OF OTHER APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G12B15/00—Cooling
  • G12B15/02—Cooling by closed-cycle fluid-circulating systems
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
  • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
  • H01S3/02—Constructional details
  • H01S3/04—Arrangements for thermal management
  • H01S3/0407—Liquid cooling, e.g. by water

Definitions

• This invention relates to a method of cooling cavities, particularly laser cavities, and in parti ⁇ cular, though not exclusively, it relates to portable laser systems.
• Efficiencies of the Neodymium YAG lasers commonly used, for instance as laser target designators, are generally low such as 1 to 1.57 0 leaving a large amount of electrical energy supplied to the lamp to be removed as heat.
• the laser 10. cavity is filled with a cooling fluid, which in the case of portable lasers especially may be high purity water, circulated by an electrically driven pump.
• the object of the present invention is to provide a method of removing gas bubbles from the cooling fluid in laser installations, the invention being not necessarily limited however to portable or battery
• the object of the invention is achieved by utilizing ducts in the housing system of the heat
• 25. may be achieved by using a junction or a venturi at or adjacent the cooling fluid outlet from the housing.
• the invention thus relates to a method of cooling 10. cavities in which the heat producing means in the cavity are submerged in a liquid coolant caused to flow through the cavity and in which the liquid coolant enters the cavity at a first region and leaves same at a second region, characterised by applying 15. a reduced pressure, relative to the pressure in the said cavity, to duct means communicating with the cavity at least at an elevated zone of the cavity where gas bubbles tend to collect, generating a reduced pressure in the duct means, and drawing 20. the gas bubbles, together with liquid coolant, through the duct means and discharging at least the liquid coolant back to the coolant supply at a point beyond the cavity where a lower pressure exists than in the cavity.
• the means comprise inlet means to the cavity, for the liquid coolant, outlet means from the cavity, for the liquid coolant, a duct from the area of the cavity where gas bubbles tend to collect to a part of the liquid coolant circuit beyond the
• FIG. 1 is a schematic view of a system using the invention.
• FIG. 2 is central longitudinal sectional view 10. of a laser assembly using a venturi to achieve the reduced pressure to draw the gas bubbles from the upper part of the cavity in the housing.
• the cavity 1 of the housing 2 has in it the heat generating means 15. such as a laser rod 3 and optical pump 4.
• liquid coolant from a tank 5 is caused by the pump 6 to flow through the line 7 into and through the cavity 1 back to the tank 5 through the line 8, but a lower pressure 20.
• area of the system is connected by the flow line 9 to the upper part 10 of the cavity 1 which is the area in which the gas bubbles collect.
• the lower pressure area 12 may be achieved by using a venturi in the line 8 leading from the 25. cavity 1 back to the tank 5, the gas being drawn from the cavity through the extraction apertures 13 and duct 14 to the flow line 9 and thus to the venturi and is then carried to the tank 5 through the line 8.
• the laser rod 3 and the optical pump 4 are mounted in the cavity 1 formed within the housing 2, and both the optical pump 4 and the laser rod 3 are sealed into the cavity by 0-rings 17.
• the cavity 1 is supplied with the coolant, 15. which is preferably high purity water, through an inlet 20 and flows thence through the cavity 1 and leaves the cavity 1 through an outlet 21 which has the low pressure area 12, in the form of a venturi, formed in it to give an area of reduced pressure 20. at the immediate outlet from the housing 2.
• the coolant which is preferably high purity water
• Forming part of the housing 2 is the duct 14 which opens into the cavity 1 through the two extraction apertures 13 and if required may also have further openings into the cavity 1, and this duct 14 communi-

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Engineering & Computer Science (AREA)
• Plasma & Fusion (AREA)
• Optics & Photonics (AREA)
• Thermal Sciences (AREA)
• Lasers (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (4)

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Family Cites Families (3)

• 1984
  • 1984-07-16 EP EP84902771A patent/EP0151155A1/de not_active Withdrawn
  • 1984-07-16 WO PCT/AU1984/000137 patent/WO1985000688A1/en not_active Application Discontinuation
  • 1984-07-16 JP JP59502805A patent/JPS61501588A/ja active Pending
  • 1984-07-23 IT IT67740/84A patent/IT1180082B/it active

Non-Patent Citations (1)

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