摘要:

An experiment which yields a value of 6.6×105Torr−1sec−1for the vibration‐vibration decay rate of thev=2 state in HF gas is described. The technique involves observation of the rise time of the HFv=2 vibrational fluorescence emanating from a gas sample pumped with a HF laser operating on av=1→v=0 transition. An analytic model which predicts the temporal behavior of the HFv=1 and collisionally populatedv=2 vibrational levels is also described. This model predicts an apparent decay rate of thev=2 fluorescence, which is twice that forv=1. Experimental measurements confirm this prediction.

ISSN:0003-6951    

DOI:10.1063/1.1654020

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Improved resistance to photodegradation for Rhodamine 6G was observed when the dye was held in a cooled solid matrix of polymethylmethacrylate. The fraction of dye bleached decreased with decreasing temperature as did the rate of bleaching. The minimum detectable quantum efficiency for photodegradation was &jgr; ≅ 10−7.

ISSN:0003-6951    

DOI:10.1063/1.1654021

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Coherent emission at 5540, 5617, and 7037 Å from Er3+ions in BaY2F8is reported. Oscillation at 5540 Å takes place at 77°K in a transition from4S3/2to a level of the4I15/2ground state at 406 cm−1. The line at 5617 Å is produced in a transition from2H9/2to a level of4I13/2at 6740 cm−1, and 7037 Å is generated in a transition from2H9/2to a4I11/2level at 10 336 cm−1. Pumping of the4I13/2state results inQswitching of the output at 5540 Å. The conditions required to produce oscillation in these lines and the detrimental effects of Yb3+are discussed.

ISSN:0003-6951    

DOI:10.1063/1.1654022

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The thickness of copper films prepared by the rf‐sputtering technique has been studied by changing the argon gas pressure and the distance between the target and the substrate. Glass disks with 110‐mm diameters were used as substrates. The relative thickness of a film was tested by using a laser beam. The distribution of copper was observed to be centralized as the argon gas pressure was lowered or the distance between the target and the substrate shortened. By using a proper arrangement, the film obtained was smooth enough for optical purposes.

ISSN:0003-6951    

DOI:10.1063/1.1654023

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

We have devised a simple new scheme of extracting tunable output from a cw dye laser. This scheme reduces the intensity of the background fluorescence of the dye to less than 10−7of the laser intensity within 10 Å of the laser line and gives an output beam whose direction is independent of the dye laser wavelength. This scheme uses no external dispersing elements and permits a continuous recording of the data as a function of dye laser wavelength.

ISSN:0003-6951    

DOI:10.1063/1.1654024

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Spurious triple‐transit signals can be rejected through phase cancellation by rotation of one transducer with respect to the other or by use of a triangular‐shaped metal film in the path between parallel transducers. Rejection is facilitated by slightly limiting the aperture via mechanical surface loading. The technique is demonstrated to give high triple‐transit suppression in delay lines with 20‐electrode‐pair transducers that give specular acoustic reflections. The technique is not found to be useful for conjugate‐matched 5‐electrode‐pair transducers, which are shown to give acoustic reflections normal to the electrodes.

ISSN:0003-6951    

DOI:10.1063/1.1654025

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

The structure of tilt grain boundaries formed by a rotation of 60° and 30° about a ⟨111⟩ axis has been examined by transmission electron microscopy. In specimens containing 30° boundaries, low‐angle dislocation arrays with a tilt angle of 2.2° are commonly observed. This is attributed to the presence of a coincidence site lattice relation at 27.8°.

ISSN:0003-6951    

DOI:10.1063/1.1654026

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

A theory is suggested to explain absorption at 10.6 &mgr; in crystals via ionic dipole‐dipole interactions. The theory indicates that minimal absorption is obtained with crystals which have symmetry with respect to optical modes and with preferred orientations of the crystals.

ISSN:0003-6951    

DOI:10.1063/1.1654027

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Vibrational relaxation measurements in several gases have been made, subsequent to vibrational pumping by picosecond pulse‐generated ``transient'' stimulated Raman scattering. This technique permits relaxation measurements at room temperature or below in a number of gases for which previously no such measurement was possible.

ISSN:0003-6951    

DOI:10.1063/1.1654028

出版商:AIP    

年代:1972

数据来源: AIP

摘要:

Holograms are produced on bismuth and paraffin films with pulsed TEA CO2laser light. Sensitivity of both films is about 0.3 J/cm2. Local resolution proved to be much better than 70 lines/mm. Capability of this holographic technique for interferometric measurements is demonstrated.

ISSN:0003-6951    

DOI:10.1063/1.1654029

出版商:AIP    

年代:1972

数据来源: AIP