FR2552894A1 - OPTICAL SYSTEM FOR USE OF A LASER BEAM FOR THERAPEUTIC USE - Google Patents

Abstract

THE INVENTION RELATES TO AN OPTICAL SYSTEM FOR USE OF A LASER BEAM FOR THERAPEUTIC USE. THE SYSTEM INCLUDES A DEVIATION MIRROR 3 TO RETURN THE LASER RADIATION 2 IN THE DIRECTION OF OBSERVATION, THIS MIRROR BEING ARRANGED BETWEEN THE MAIN OBJECTIVE 4 AND THE OCCULAR 5 OF THE OBSERVATION INSTRUMENT, A CORRECTIVE OPTIC 6 INTENDED TO COMPENSATE FOR THE CHROMATIC ABERRATION CAUSED BY THE DIFFERENCE IN WAVELENGTH BETWEEN LASER LIGHT AND OBSERVATION LIGHT BEING ARRANGED IN FRONT OF THE DEVIATION MIRROR 3. THE INVENTION FOUND ITS MAIN APPLICATION IN OPHTHALMOLOGICAL SURGERY.

Description

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  An optical system for processing and observation apparatus using laser radiation, with a deflection mirror for returning the beam

  laser in the direction of observation.

  The laser light has a therapeutic application, for example in ophthalmology US Patent 3,769,963 describes an operating microscope which, for therapeutic applications, can be combined with a laser system Laser radiation

  Therapeutically, in this apparatus of the current state of the art, passes outside the operating microscope.

  In compact instruments, it is desirable for the laser radiation to pass through the optics of the observation instrument. This creates a problem: the therapeutic beam and the observation beam have different wavelengths, which creates significant chromatic aberrations

  for the wavelength ranges used.

  The object of the invention is therefore to create an optical system that compensates for the chromatic aberrations that occur when the optics used for the formation of

  the image uses different wavelength ranges.

  This object is achieved according to the invention by the fact that a deflection mirror is disposed between the main objective and the eyepiece of the observation instrument, and that, when looking in the direction of observation, a corrective optics, intended to compensate for the resulting chromatic aberration

  the use of a laser light and the observation light, is arranged in front of the deflection mirror.

  An advantageous exemplary embodiment of the optical system according to the invention is characterized in that, for therapeutic laser radiation of wavelength λ 1 = 1064 nm, a wavelength of the target laser radiation at λ = 633 nm and a wavelength of the observation light of 480-644 nm, the lens has the following characteristics:

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  s 1 = -119.4 (nd) (ad) r 1 = 486.97 d 1 = 7 N 1 = 1.6209 v 1 = 60.3 r 2 = -105.93 d 2 = 0.3 r 3 = 427.81 d 3 = 4 N 3 = 1.8052 V 3 = 25.4 r 4 = 78, 298 d 4 = 0.3 r 5 = 79.719 d 5 = 7.7 N 5 = 1.5532 V 5 63.5 r 6 = -227.12 s I = 0 and that the corrective optics have the following characteristics s = O r 1 = -137.25 d = 7 N = 1.8052 v 1 = 25.4 r 2 = -91.07 dn 2 = 7 2 1.6177 v 2 = 49.8 r 3 = -170.31 s' = co The advantages that can be achieved thanks to the optical system according to the invention reside in particular in that the optics of a commercially available diagnostic device can be passed through the laser radiation necessary for therapeutic applications, without resulting in any deterioration of the image. Moreover, the fact that the laser radiation passes through the optics of an observation instrument allows a compact and space-saving construction of

the laser treatment apparatus.

  An exemplary embodiment of the invention is shown in the drawing and is described in more detail below. The single FIGURE is a schematic representation of the optical system according to FIG.

  the invention, installed in a diagnostic or observation device.

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  In the figure, reference numeral 1 designates the eye of the patient

  arrow 2 indicates the direction of the laser radiation used.

  The latter may consist for example of therapeutic radiation, of wavelength λ = 1064 nm, and, from a second laser source, a sighting beam of wavelength λ = 633 nm. 3 deflects the laser light by falling on the eye of the patient 1 after passing through the main lens 4 The deflection mirror 3 is semi-transparent to the aiming beam, so that the latter can be observed by the observation optics 5 of a

  slit lamp, operating microscope or other observing apparatus Mark 6 denotes corrective optics.

  Since objective 4 is corrected for the 1064 and 633 nm laser wavelength ranges, correction optics 6 are corrected to compensate for chromosomal aberration for visible light (480-644 nm) observation. of focus caused by the correction of the main objective 4 The

  The combination of the main objective 4 and the corrective optics 6 is therefore also corrected for the range of 480 to 644 nm.

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Claims (3)

claims   An optical system for laser processing and observation apparatus, with a deflection mirror (3) for returning the laser radiation (2) in the direction of observation, characterized in that the deflection mirror (3) is arranged between the main objective (4) and the eyepiece (5) of the observation instrument and that, when looking in the direction of observation, a corrective optics (6), intended to compensate the chromatic aberration due to the difference in wavelength between the laser light and the observation light,   is disposed in front of the deflection mirror (3).   Optical system according to claim 1, characterized in that, for a wavelength of the therapeutic laser radiation at 1 = 1064 nm, a wavelength of the laser aiming laser at 2 = 633 nm and a length of Observation light wave from 480 to 644 nm, the lens has the following characteristics: s = -119.4 (nd) (Vd) r 1 = 486.97 d 1 7 N 1 = 1.6209 v 1 = 60.3 r 2 = -105.93 d 2 = 0.3 r 3 = 427.81 d 3 = 4 N 3 = 1.8052 v 3 = 25.4 r 4 = 78.298 d 4 = 0.3 r 5 = 79.719 d 5 = 7.7 N 5 = 1, 5532 v 5 = 63.5 r 6 = -227.12 s' and that the corrective optics has the following characteristics: s = r 1 = -137, 25 d = 7 N 1 = 1.8052 v 1 = 25, 4 r 2 = -91.07 d 2 = 7 S '= 00 2552894 V 2 = 49.8 n 2 = 1.6177 r 3 = -170.31