There is a gradient vector potential in electromagnetic field. A tensor of the internal tension of electromagnetic field has been derived from it. The existence of this tension is the origin of the phenomena of diffraction, interference etc.

Boron isotope enrichment is obtained by selectively exciting the ν vibrational mode with multiple-photon absorption using a TEA CO2 laser, as a result, 11BOl3 dissociates and its fragments interact with dry atmosphere. Various experimental conditions affecting the enrichment coefficient were observed. Solid and gaseous products of the irradiation were measured by infrared absorption spectroscopy and mass speotroscopy. The maximum enrichment coefficient obtained was 2.3. In an experiment of greater scale, some macroscopic measurable quantities were obtained, and the productivity was about milligrams an hour. On analysing the gaseous products evaporating from a frozen sample of the residual gas, the broadening and anomalous intensification of the 1,000 cm-1 IR band were found.

General considerations for increasing the circuit efficiency and laser output power were analyzed. The segmented structure of Blumlein circuit and the results of corona preionization were studied; the effect of electrodes with unequal spacing on laser output in two directions were measured. The existence of "travelling-wave excitation" in the system are denied, and a new explanation for the experimental results are given.

A pulsed discharging argon ion laser with repetitive frequency of 50-200 Hz is described. The inner diameter of the discharge tube is 6 mm, the tube length is 860 mm, the overall length of the resonator is 1200 mm, and the pulse width is 9μs. An output of 30-50 W can be obtained at the optimum operation current.

Parameters and sizes of components and parts in the experimental setup for a GW dye laser are presented, jetting and cycling system of dye solution are described. Main experimental results obtained until recently are presented, which include oscillation threshold, laser conversion efficiency, the maximum output power, and the effect of additive COT on the conversion efficiency. Main problems of the device are discussed and suggestions for improvement are raised.

A linear flashtube pumped rhodamine 6G dye laser was built. The laser pulse energy is up to 27mj, and the halfwidth of laser pulse is 1μS. Laser efficiency is 0.1%. Spectral width of 40 A° is obtained by tuning a prizm. Pulse repetition rate of 1 and 2 pps was obtained and the performances of the device were studied.

A Fresnel rhomb combined with a 1.06 μm multilayer dielectric film polarizer forms an isolator with an effective diameter of 60 mm. An extinction coefficient of over 102 has been obtained. It is shown in the experiments that the design of high power laser is simplified and their operation is facilitated by using this isolator.

An experimental setup for a two staged giant pulse ruby laser is described together with its adjusting and matching techniques. A synchronously triggering circuit with high stability and strong anti-disturbance capability is introduced.

Samples of GaAs implanted with tin were irradiated with a Q-switohed ruby laser (-1J/cm2, 30-40 ns). Investigation on proton channeling and electron diffraction showed that the amorphous layer of samples implanted with 60 keV or 300 keV Sn ions was recrystallized by laser irradiation, and the dopant atoms were in substitutional sites. The maximim concentration of GaAs carriers was up to 1×1019/cm3 after annealing, it is 20 times higher than that of the heat annealed samples.

A new method for inspection of fineness and flaws on the axle tip of miniature instruments with laser is described. It has been proved in practice that the new method has the advantages of simplicity, reliability and fast speed for inspection.

The characteristics of the error signal in a laser frequency stabilizer are discussed. A new method for controlling the length of laser cavity is presented. The relative stability for the two-frequency laser stabilizer is up to 5×10-10.

Laser Delegation of Instrument Society of China was invited to attend the 7th Conference on Laser Engineering and Application in United States. The authors personally learned the frontier trends and the developments in depth in the field of laser science. The successful work by the American scientists has left deep impression on them.