- Email: [email protected]
Picosecond dye laser pulses
Recent developments Picosecond dye laser pulses
Improved
A technique for generating tunable picosecond pulses from an organic dye laser has been developed at IBM’s Thomas J.Watson Research Center. Pulses of as short as 150 ps were obtained in trains of ten. These pulses have a tunable wavelength and are sufficiently reproducible from pulse to pulse to allow sampling scope techniques to be used in their display.
A new infra-red laser searchlight system which maintains critical components at cryogenic temperatures without the use of a vacuum has been developed by RCA. Previously infra-red laser illuminators have needed an insulating vacuum around the injection diodes to maintain the very low temperatures at which they perform best. The RCA searchlight uses in place of the conventional cooling system an open cycle liquid nitrogen cooler.
The dye used (rhodamine 6G in ethanol) is pumped by a nitrogen laser and a saturable absorber is used to obtain mode-locking. The nitrogen laser pump puts out 10 ns pulses which accounts for the very short train of picosecond pulses. Successive tracings of pulses were shown to coincide on the sampling oscilloscope to within 50 ps. This repeatability was maintained as the output of the dye was tuned over 200 A using a grating in the cavity. The high repetition rate of the nitrogen laser pump permits the use of sampling oscilloscopes for display of measurements and the tunability and stability of pulses from the dye provide a very well-defined source of radiation. It should be possible to extend this technique to other organic dyes at higher frequencies.
laser searchlight
Angular positioning locations
This new illuminator was developed for use in night vision military equipment under contract to the US Army Night Vision Laboratories. One of the great problems this new design solves is the difficulty of maintaining a vacuum under field conditions. Also components can easily be repaired or replaced without having to break a vacuum and then recreate it before resuming operation. Thirty-five gallium arsenide injection laser diodes are arranged in six arrays within the illuminator. These produce a power output of 4 W at 1.4% duty cycle. RCA Aerospace System Division, Burlington, Mass, USA.
from remote
Saunders Associates Inc has developed an electro-optical instrument which can determine precise angular positions from a remote location. This device uses a pulsed xenon lamp which projects a wide beam - 6’ by 8” - able to be sighted visually up to a mile away even in the brightest sunlight. The beam is divided electro-optically into a right and left-hand sector, each of which is encoded for easy identification. These encoded sectors combine at the beam’s centre to form a third very narrow sector, of 20 - 40 arc seconds wide, which is identified by its own separate code. The advantage of a xenon beam over a laser beam is that a small laser beam may tend to be difficult to locate and maintain. The xenon beam since it covers a wide arc overcomes this problem and the operator can easily determine which way to move in order to approach the centre. The entire system, known as the GNS22P consists of a projector, a pulser, and a receiver. The receiver is optional since detection and interpretation can
IBM, Thomas J. WatsonResearch Center, PO BOX218, Yorktown Heights, New York 10598, USA. Illuminating
microscope
A variable power industrial microscope with an illumination from either a cold cathode or high intensity fibre optic source is now being marketed by Ealing Beck Limited. Fig. 1 shows the microscope in use for observation of micro-miniaturised components, but it can be mounted for production line or laboratory work. The fibre optic light guides from a 75 W tungsten lamp can be used in two modes, independently or corn bined. Magnifications of up to x 40 can be obtained on standard models, or x 80 with specially developed eyepieces. The clear working distance is 100 m at all magnifications with a focusing travel of 35 mm. Fig. 1
Ealing Beck Limited, Greycaine Road, Watford, Herts, UK.
Microscope
being used for observation
components Ferranti
on a bonding
machine
of micro-miniaturised
designed and installed
by
Ltd.
Optics and Laser Technology
November 1971
249
Improved
A technique for generating tunable picosecond pulses from an organic dye laser has been developed at IBM’s Thomas J.Watson Research Center. Pulses of as short as 150 ps were obtained in trains of ten. These pulses have a tunable wavelength and are sufficiently reproducible from pulse to pulse to allow sampling scope techniques to be used in their display.
A new infra-red laser searchlight system which maintains critical components at cryogenic temperatures without the use of a vacuum has been developed by RCA. Previously infra-red laser illuminators have needed an insulating vacuum around the injection diodes to maintain the very low temperatures at which they perform best. The RCA searchlight uses in place of the conventional cooling system an open cycle liquid nitrogen cooler.
The dye used (rhodamine 6G in ethanol) is pumped by a nitrogen laser and a saturable absorber is used to obtain mode-locking. The nitrogen laser pump puts out 10 ns pulses which accounts for the very short train of picosecond pulses. Successive tracings of pulses were shown to coincide on the sampling oscilloscope to within 50 ps. This repeatability was maintained as the output of the dye was tuned over 200 A using a grating in the cavity. The high repetition rate of the nitrogen laser pump permits the use of sampling oscilloscopes for display of measurements and the tunability and stability of pulses from the dye provide a very well-defined source of radiation. It should be possible to extend this technique to other organic dyes at higher frequencies.
laser searchlight
Angular positioning locations
This new illuminator was developed for use in night vision military equipment under contract to the US Army Night Vision Laboratories. One of the great problems this new design solves is the difficulty of maintaining a vacuum under field conditions. Also components can easily be repaired or replaced without having to break a vacuum and then recreate it before resuming operation. Thirty-five gallium arsenide injection laser diodes are arranged in six arrays within the illuminator. These produce a power output of 4 W at 1.4% duty cycle. RCA Aerospace System Division, Burlington, Mass, USA.
from remote
Saunders Associates Inc has developed an electro-optical instrument which can determine precise angular positions from a remote location. This device uses a pulsed xenon lamp which projects a wide beam - 6’ by 8” - able to be sighted visually up to a mile away even in the brightest sunlight. The beam is divided electro-optically into a right and left-hand sector, each of which is encoded for easy identification. These encoded sectors combine at the beam’s centre to form a third very narrow sector, of 20 - 40 arc seconds wide, which is identified by its own separate code. The advantage of a xenon beam over a laser beam is that a small laser beam may tend to be difficult to locate and maintain. The xenon beam since it covers a wide arc overcomes this problem and the operator can easily determine which way to move in order to approach the centre. The entire system, known as the GNS22P consists of a projector, a pulser, and a receiver. The receiver is optional since detection and interpretation can
IBM, Thomas J. WatsonResearch Center, PO BOX218, Yorktown Heights, New York 10598, USA. Illuminating
microscope
A variable power industrial microscope with an illumination from either a cold cathode or high intensity fibre optic source is now being marketed by Ealing Beck Limited. Fig. 1 shows the microscope in use for observation of micro-miniaturised components, but it can be mounted for production line or laboratory work. The fibre optic light guides from a 75 W tungsten lamp can be used in two modes, independently or corn bined. Magnifications of up to x 40 can be obtained on standard models, or x 80 with specially developed eyepieces. The clear working distance is 100 m at all magnifications with a focusing travel of 35 mm. Fig. 1
Ealing Beck Limited, Greycaine Road, Watford, Herts, UK.
Microscope
being used for observation
components Ferranti
on a bonding
machine
of micro-miniaturised
designed and installed
by
Ltd.
Optics and Laser Technology
November 1971
249