摘要:

Students in our upper-division/graduate physical optics laboratory course assemble a high-finesse Fabry–Perot interferometer (FPI) from components, mode-match it to a helium–neon (HeNe) laser, and examine some of the FPI system’s properties and uses. Here, we specify the necessary equipment and describe experimental procedures. For example, the experiments use the FPI’s high spectral resolution to monitor the laser’s behavior as it warms up; in another experimental step, they confront the issue of the photodetection system’s electronic bandwidth. We also provide a review of Gaussian beam formulas and detail their use in mode-matching calculations.

ISSN:0002-9505    

DOI:10.1119/1.18572

出版商:American Association of Physics Teachers    

年代:1997

数据来源: AIP

摘要:

We present an alternative to the standard method of solution of the Dirac equation for a particle in a Coulomb potential, which hews closer to the more familiar solution of the nonrelativistic Schrödinger equation. The bound-state wave functions so obtained are also closer in form to the nonrelativistic Schrödinger wave functions and make the transition to this limit more evident. The equivalence of these and the “standard” solution form of the Dirac wave functions is demonstrated in the Appendix, which, at the same time, shows the advantage of a new trigonometric parametrization in the algebraic manipulation of relativistic quantities.

ISSN:0002-9505    

DOI:10.1119/1.18531

出版商:American Association of Physics Teachers    

年代:1997

数据来源: AIP

摘要:

The notion of the quantum defect is important in atomic and molecular spectroscopy and also in unifying spectroscopy with collision theory. In the latter context, the quantum defect may be viewed as an ancestor of the phase shift. However, the origin of the term “quantum defect” does not seem to be explained in standard textbooks. It occurred in a 1921 paper by Schrödinger, preceding quantum mechanics, yet giving the correct meaning as an index of the short-range interactions with the core of an atom. We present the early history of the quantum-defect idea, and sketch its recent developments.

ISSN:0002-9505    

DOI:10.1119/1.18532

出版商:American Association of Physics Teachers    

年代:1997

数据来源: AIP

摘要:

An elementary analysis is given for some familiar wave patterns observed along a vertical water jet. The results follow from the fact that the group velocity of the short axially symmetric capillary waves is greater than the phase velocity, while the converse is true for the long waves having an azimuthal dependence. It is found that there is a close analogy between these stationary patterns and the two-dimensional wave pattern in the fishing-line problem.

ISSN:0002-9505    

DOI:10.1119/1.18533

出版商:American Association of Physics Teachers    

年代:1997

数据来源: AIP

摘要:

A computer simulation is presented of a one-dimensional particle migration by local hopping of Chandrasekhar type with no local bias but with hopping rates which vary with position in the system. Of the two possible diffusion equations to represent the process, one is clearly shown to be wrong while the other gives an accurate representation of the evolution of the system. The cases of bothreflectingandabsorbingboundaries are considered, and in the latter case a sum-rule previously derived for this type of random migration is verified. The concept of local particletrafficis introduced. Arguments are presented to show that the spatial traffic distribution gives a better insight into some aspects of particle activity than the probability distribution.

ISSN:0002-9505    

DOI:10.1119/1.18534

出版商:American Association of Physics Teachers    

年代:1997

数据来源: AIP

摘要:

The solution of the time-independent Schrödinger equation is fractionated by solving a corresponding Riccati equation. Simple particular solutions of the Riccati equation are used to construct exact ground state energy eigenvalues and eigenfunctions of otherwise complex problems without solving for the complete energy spectrum. In some instances, a partial series of the complete spectrum is also obtained with little extra effort. A procedure for obtaining the complete energy spectrum from the Riccati equation is also presented, and the entire method is illustrated by detailed analysis of several examples.

ISSN:0002-9505    

DOI:10.1119/1.18535

出版商:American Association of Physics Teachers    

年代:1997

数据来源: AIP

摘要:

The classical dynamics of two interacting particles of equal mass and equal or opposite charge, moving in a plane and a perpendicular magnetic field, is discussed. The simplest trajectories are similar to those of a single particle in the presence of crossed electric and magnetic fields (Hall configuration). Such motion occurs over a ribbon that may be straight (for opposite charges), or bent into a circle (for identical particles).

ISSN:0002-9505    

DOI:10.1119/1.18536

出版商:American Association of Physics Teachers    

年代:1997

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.18537

出版商:American Association of Physics Teachers    

年代:1997

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.18748

出版商:American Association of Physics Teachers    

年代:1997

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.18538

出版商:American Association of Physics Teachers    

年代:1997

数据来源: AIP