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New optical bench
CURRENT TOPICS
Sept. ,962.1
and one 5 ft. in diameter) as well as instrumentation for controlling and recording operations are included in the system. The huge space chamber was fabricated at N R C ' s Newton, Mass., plant, and barged to Long Island where it was trucked into the Syosset location. This operation involved special road permits, movement of telephone wires, and the use of a special telephone crew enroute. Also, road movements were restricted to low traffic density hours.
Gaseous
Optical
Masers.--Two
new gaseous optical m a s e r s - - o n e using a mixture of neon and oxygen, the other of argon and o x y g e n - - h a v e been announced by Bell Telephone Laboratories. Both devices radiate in the near infrared at a wavelength of 8446 angstroms. This marks a major technological advance because the underlying physical principle suggests the advent of a whole new family of gaseous optical masers. Also, it immediately provides a new frequency for optical communications. Optical maser action in neon-oxygen and argon-oxygen is made possible by "dissociative excitation transfer." It is the first time that this excitation mechanism has been used in an optical maser.
To operate the masers, Bell Laboratories scientists mix molecular oxygen with neon or argon and excite the mixture with a radiofrequency discharge. Energy transferring from the neon or argon to the oxygen molecule results in its dissociation into two atoms. One of these atoms attains an excited state, either immediately or very shortly thereafterwards, from which it radiates the 8446-angstrom line. Maser oscillation takes place in a quartz-tube resonator which is a modification of the one used for the original
249
gas optical maser experiments conducted at Bell Laboratories. The present device is a 2-meter long tube with external confocal mirrors which also were developed at Bell Laboratories. The masers contain a ratio, by pressure respectively, of approximately 70 to 1, neon to oxygen, and approximately 40 to 1, argon to oxygen. In both cases output power is about two milliwatts. The experiments suggest that the mechanism of dissociative excitation of a molecule by energy transfer from a metastable atom may be more generally useful in optical maser technology than the inelastic atom-atom collisions responsible for maser action in helium-neon mixtures. In the latter case, electrons in the discharge created by the rf generator excite helium atoms to their metastable state, which is comparable in energy to an upper state of neon. As a result, the helium atoms can impart their energy to the neon atoms by collisions. The neon atoms then radiate to a lower energy level, creating the maser oscillation. N e w Optical B e n c h . - - A new optical laboratory unit that fills the gap between the expensive research optical bench and the elementary meter stick bench is now being made by E. Leybold's Nachfolger, Cologne, West Germany, and distributed by LaPine Scientific Co., Chicago. This optical laboratory unit includes with the optical bench 31 auxiliary pieces of apparatus that bring to the instructor in optics unmatched versatility, convenience, and economy. A wide range of experiments can be performed in reflection, refraction, diffraction, color dispersion, etc. Equipment to demonstrate the construction of the eye, microscope, and telescope are included.
250
CURaEWr T o p i c s
A particular advantage to the instructor is the fact that more elaborate pieces of equipment can be added to this basic unit as the course of instruction or research project in optics advances from its early stages to more advanced stages. Basic components of the new optical laboratory unit are: 1. The optical bench--This bench fills the gap between the elementary meter stick bench and the expensive research optical bench. The unique construction holds all optical elements in position for true alignment. The versatile design allows it to be tilted and swiveled for exhibiting in different directions. It is also easily portable. 2. The optical disk--This disk is designed especially for mounting on the bench with proper alignment of all elements. 3. The lamp h o u s e - - A low-voltage lamp with a very small filament. There is provision for centering the lamp filament. 4. Lenses and prisms--All lenses and prisms are constructed of high grade optical glass. Other items of equipment include carriages, single-lens condenser and diaphragm, diaphragm with three slits, colored glass plates, transparent screen, prism holder, and a diffraction diaphragm with 3 wires. Accessory equipment includes a Bunsen clamp, support base, support rods, and a transformer. Included with the optical apparatus is a manual which explains and illustrates 34 basic experiments in reflection, refraction, diffraction, color dispersion, etc. that can be performed with this equipment. The experiments shown in the manual explain exactly what equipment is used, the demonstration procedure, and techniques for demonstrating optics with them.
[J.F.I.
Miniature Timing Light Generator.--The development of a new highly accurate miniature timing light generator for high speed film timing applications has just been announced by Adtrol Electronics Inc., Philadelphia, Pa. The generator can trigger ten or more type NE-2 or NE-51 neon glow lamps in moving-film cameras for applications where it is necessary to measure elapsed time between events occurring at rapid rates, such as the photo recording of an in-flight missile. In operation the generator produces precisely-timed pulses which activate the neon lamps in the cameras leaving accurate timing marks on the film at pre-selected intervals controlled by the generator. Advantages of the Adtrol unit over conventional timing light generators include smaller size, lower cost and greater driving power. The Model TLG-111 generates a 375-volt pulse with 30 usec duration. Frequency is selected by a front panel switch at rates of 10, 100, and 1,000 cps. Calibration accuracy is 0.1 per cent with a frequency stability of 0.01 per cent. Lock-type screwdriver adjustments are provided for ease of frequency calibration with any accurate time standard. The generator can be operated from any 28-volt d. c. source at 150 mw average power. Dimensions of the unit are 5 in. × 3½ in. x 2 in. and it weighs approximately one pound.
Machine Diagnoses Its Own Failures.--An electronic telephone switching system that diagnoses its own failures when they occur and tells maintenance men where to look for the trouble in a "dictionary" it helped "write" has been developed at Bell Telephone Laboratories. The system also discovered methods of running it-
Sept. ,962.1
and one 5 ft. in diameter) as well as instrumentation for controlling and recording operations are included in the system. The huge space chamber was fabricated at N R C ' s Newton, Mass., plant, and barged to Long Island where it was trucked into the Syosset location. This operation involved special road permits, movement of telephone wires, and the use of a special telephone crew enroute. Also, road movements were restricted to low traffic density hours.
Gaseous
Optical
Masers.--Two
new gaseous optical m a s e r s - - o n e using a mixture of neon and oxygen, the other of argon and o x y g e n - - h a v e been announced by Bell Telephone Laboratories. Both devices radiate in the near infrared at a wavelength of 8446 angstroms. This marks a major technological advance because the underlying physical principle suggests the advent of a whole new family of gaseous optical masers. Also, it immediately provides a new frequency for optical communications. Optical maser action in neon-oxygen and argon-oxygen is made possible by "dissociative excitation transfer." It is the first time that this excitation mechanism has been used in an optical maser.
To operate the masers, Bell Laboratories scientists mix molecular oxygen with neon or argon and excite the mixture with a radiofrequency discharge. Energy transferring from the neon or argon to the oxygen molecule results in its dissociation into two atoms. One of these atoms attains an excited state, either immediately or very shortly thereafterwards, from which it radiates the 8446-angstrom line. Maser oscillation takes place in a quartz-tube resonator which is a modification of the one used for the original
249
gas optical maser experiments conducted at Bell Laboratories. The present device is a 2-meter long tube with external confocal mirrors which also were developed at Bell Laboratories. The masers contain a ratio, by pressure respectively, of approximately 70 to 1, neon to oxygen, and approximately 40 to 1, argon to oxygen. In both cases output power is about two milliwatts. The experiments suggest that the mechanism of dissociative excitation of a molecule by energy transfer from a metastable atom may be more generally useful in optical maser technology than the inelastic atom-atom collisions responsible for maser action in helium-neon mixtures. In the latter case, electrons in the discharge created by the rf generator excite helium atoms to their metastable state, which is comparable in energy to an upper state of neon. As a result, the helium atoms can impart their energy to the neon atoms by collisions. The neon atoms then radiate to a lower energy level, creating the maser oscillation. N e w Optical B e n c h . - - A new optical laboratory unit that fills the gap between the expensive research optical bench and the elementary meter stick bench is now being made by E. Leybold's Nachfolger, Cologne, West Germany, and distributed by LaPine Scientific Co., Chicago. This optical laboratory unit includes with the optical bench 31 auxiliary pieces of apparatus that bring to the instructor in optics unmatched versatility, convenience, and economy. A wide range of experiments can be performed in reflection, refraction, diffraction, color dispersion, etc. Equipment to demonstrate the construction of the eye, microscope, and telescope are included.
250
CURaEWr T o p i c s
A particular advantage to the instructor is the fact that more elaborate pieces of equipment can be added to this basic unit as the course of instruction or research project in optics advances from its early stages to more advanced stages. Basic components of the new optical laboratory unit are: 1. The optical bench--This bench fills the gap between the elementary meter stick bench and the expensive research optical bench. The unique construction holds all optical elements in position for true alignment. The versatile design allows it to be tilted and swiveled for exhibiting in different directions. It is also easily portable. 2. The optical disk--This disk is designed especially for mounting on the bench with proper alignment of all elements. 3. The lamp h o u s e - - A low-voltage lamp with a very small filament. There is provision for centering the lamp filament. 4. Lenses and prisms--All lenses and prisms are constructed of high grade optical glass. Other items of equipment include carriages, single-lens condenser and diaphragm, diaphragm with three slits, colored glass plates, transparent screen, prism holder, and a diffraction diaphragm with 3 wires. Accessory equipment includes a Bunsen clamp, support base, support rods, and a transformer. Included with the optical apparatus is a manual which explains and illustrates 34 basic experiments in reflection, refraction, diffraction, color dispersion, etc. that can be performed with this equipment. The experiments shown in the manual explain exactly what equipment is used, the demonstration procedure, and techniques for demonstrating optics with them.
[J.F.I.
Miniature Timing Light Generator.--The development of a new highly accurate miniature timing light generator for high speed film timing applications has just been announced by Adtrol Electronics Inc., Philadelphia, Pa. The generator can trigger ten or more type NE-2 or NE-51 neon glow lamps in moving-film cameras for applications where it is necessary to measure elapsed time between events occurring at rapid rates, such as the photo recording of an in-flight missile. In operation the generator produces precisely-timed pulses which activate the neon lamps in the cameras leaving accurate timing marks on the film at pre-selected intervals controlled by the generator. Advantages of the Adtrol unit over conventional timing light generators include smaller size, lower cost and greater driving power. The Model TLG-111 generates a 375-volt pulse with 30 usec duration. Frequency is selected by a front panel switch at rates of 10, 100, and 1,000 cps. Calibration accuracy is 0.1 per cent with a frequency stability of 0.01 per cent. Lock-type screwdriver adjustments are provided for ease of frequency calibration with any accurate time standard. The generator can be operated from any 28-volt d. c. source at 150 mw average power. Dimensions of the unit are 5 in. × 3½ in. x 2 in. and it weighs approximately one pound.
Machine Diagnoses Its Own Failures.--An electronic telephone switching system that diagnoses its own failures when they occur and tells maintenance men where to look for the trouble in a "dictionary" it helped "write" has been developed at Bell Telephone Laboratories. The system also discovered methods of running it-