Optical Mounts Research Articles

Optics

Edmund Scientific's new optical mounts can be used for prototype modelling and design troubleshooting. Designed to accept 25 mm optics, each screw-together precision machined mount has complementary 42 × 75 mm “T” threads and matching barrel dimensions.

Low-cost adjustable mirror mount

Complex optical systems commonly employ adjustable optical mounts for alignment purposes. The design of a low-cost adjustable mirror mount that provides simple tilt and height adjustments is described. This mirror mount employs conventional machining and standard off-the-shelf hardware and is, therefore, very suitable for low-cost rapid prototyping applications. A diamond-machined metal mirror is directly assembled to the mount with three screws and two precision dowel pins. The adjustments are provided by three spring-loaded screws between the mount and a fixed base plate. Two set screws are used for locking purposes after the adjustments have been made.

The minimization of ac phase noise in interferometric systems

A simple step-by-step procedure, including several novel techniques discussed in the Appendices, is given for minimizing ac phase noise in typical interferometric systems such as two-beam interferometers, holographic setups, four-wave mixers, etc. Special attention is given to index of refraction fluctuations, direct mechanical coupling, and acoustic coupling, whose importance in determining ac phase noise in interferometric systems has not been adequately treated. The minimization procedure must be carried out while continuously monitoring the phase noise which can be done very simply by using a photodiode measurement of the interferometer output. Supplementary measurements using a microphone and accelerometer will also be helpful in identifying the sources of phase noise. Emphasis is placed on new techniques or new modifications of older techniques which will not usually be familiar to most workers in optics. Thus, the necessity of eliminating the effects of index of refraction fluctuations which degrade the performance of all interferometers is pointed out as the first priority. A substantial decrease of the effects of all vibrating, rotating, or flowing masses (e.g., cooling lines) in direct contact with the optical table will also have to be carefully carried out regardless of the type of interferometric system employed. It is recommended that this be followed by a simple, inexpensive change to a novel type of interferometer discussed in Appendix A which is inherently less sensitive to mechanical vibration. Such a change will lead to a reduction of both low-frequency and high-frequency ac phase noise by more than an order of magnitude and can be carried out for all interferometers with the exception of multiple pass optical systems and high-resolution FFT spectrometers. It is pointed out that most homemade air bladder vibration isolators are used incorrectly and do not provide sufficient reduction in the contribution of floor vibrations to phase noise. Several simple trampoline-type air bladder vibration isolator systems are described which are comparable in performance to commercial systems. With the exception of very nonrigid or undamped optical tables, the dominant source of ac phase noise at this point will usually be due to acoustic coupling to the optical components and mounts themselves. This means not only that the optical components and mounts must be rigid but that the mechanical coupling between the table and the mounts, as well as the coupling between the mounts and components themselves, be as rigid as possible. An additional damping of optical mounts beyond that generally found in commercial mountings will also have to be carried out to obtain a further reduction of phase noise. A simple damping technique employing an additional mass and an intermediate damping layer is described which will significantly improve the performance of both homemade and commercial optical mounts. Similar damping techniques which are especially suitable for homemade optical tables and breadboards are also considered.

Optical Surface Mount Technology

Optical Surface Mount Technology

Optical Surface Mount Technology

Optical surface mount technology (O-SMT) is proposed on the analogy of surface mount technology widely employed in current electronics, in order to meet growing serious problems in manufacturing processes for practical optoelectronic systems.

Design and performance of a direct-reading, multichannel spectrometer for the determination of chlorinated purgeable organic compounds by flame infrared-emission spectrometry

The feasibility of determining chlorinated, purgeable organic compounds (POCs) in aqueous samples by flame infrared-emission (FIRE) spectrometry was evaluated with a specially designed, multichannel, dispersive spectrometer having sufficient resolving power to prevent interference from large amounts of non-halogenated POCs that could also be present in the sample. The polychromator was based on a Czerny—Turner optical mounting with a 0.15-m focal length, a nominal focal ratio of f/3, and a reciprocal linear dispersion of 0.15 μm/mm in the first order. The HCl and CO 2 infrared emission bands (3.77 and 4.42 μm, respectively) were monitored in two analytical channels, while a third reference channel, used for background subtraction, monitored the H 2O background emission at 2.8 μm. Instrumental performance was evaluated with dichloromethane, trichloromethane, trichloroethylene, 1,1,2,2-tetrachloroethane and monochlorobenzene as test compounds, and parameters such as the linear dynamic range, reproducibility, detection limit and signal-to-noise ratio, and extent of spectral crosstalk between channels were determined. The feasibility of performing a quantitative analysis of a two-component mixture of dichloromethane and trichloromethane at trace levels was demonstrated.

Design and implementation of an inexpensive target scanner for the growth of thin films by the laser-ablation process

The design of a target scanner that is inexpensive and easy to construct is described. Our target scanner system does not require an expensive personal computer to raster the laser beam uniformily over the target material, unlike the computer driven target scanners that are currently being used in the thin-film industry. The main components of our target scanner comprise a bidirectional motor, a two-position switch, and a standard optical mirror mount.

Identification of concentration gradients in a glow discharge atomisation cell using a low-cost XY? adjustable platform

A simple, inexpensive optical mount for use with the Atomsource glow discharge direct solids atomiser has been designed and built. This mount allows adjustment of the atomiser in the horizontal, vertical and rotational (in the horizontal plane) modes relative to the optical path. The mount has been used in conjunction with the associated spectrometer, the Analyte 16 Atomic Absorption Spectrometer, to illustrate the presence of concentration gradients of sputtered species within the Atomsource plasma. From these data, general mass transport patterns and regions of enhanced ionisation in the Atomsource can be identified. The optimum location in the plasma from which to sample using atomic absorption detection of sputtered material can also be established.

Microwave tuning devices as mirror mount adjusters

Microwave tuning screws, which are of low cost and readily available, are noted to be exceptionally suitable for use as pre-set optical mirror mount adjusters.

Two-color CO2 interferometer with single Bragg cell and improved vibration compensation at 3.39 μm

A single-chord CO2 (10.6-μm) He–Ne (3.39-μm) two-color laser interferometer which has been developed for the ETA-BETA II RFP machine is presented. Compared to the usual 0.633-μm vibration compensation systems, the 3.39-μm interferometer allows faster optical path-length variations to be measured without losing fringes, can stand larger angular deflections of the beams (e.g., due to vibrations of the optic mounts) without losing alignment, and uses the same acousto-optic modulator as the CO2 system, thus minimizing the differences in the optical path of the two interferometers. The instrument has been extensively utilized on ETA-BETA II, where line density variations larger than 1020 m−2 and occurring in less than 4 μs can be routinely measured and the residual error after vibration compensation is ≊2×1018 m−2. Some further developments of the diagnostic are presented, which are presently underway or planned.

New compliant mounting for coupling microlensed fibers to semiconductor laser diodes

We demonstrate an optical fiber mounting device which allows microlensed fibers to be pressed repeatedly against the cleaved facets of semiconductor laser diodes without causing impact damage to the facet. The device constrains the fiber against lateral movement while using the resilience of a second fiber acting as a weak spring to allow compliance along the optical axis. Stability of the microlensed fiber is not affected.

Heterodyne interferometers: Practical limitations and improvements

Heterodyne interferometers are very sensitive tools for probing surface displacements. The wide bandwidth (about 1 GHz) and the high resolution allow many applications in the field of bulk (BAW) and surface acoustic waves (SAW). However all these interferometers exhibit low-frequency phase fluctuations depending on the optical mounting. Recent versions of these instruments reduce the noise down to the theoretical value. This paper shows the spectral density of phase fluctuations for three different configurations. The results are analysed and the noise sources are identified.

Optics mount with 180° angle of view from both sides

A simple design for a stable, general-purpose optics mount is described, with independent, self-locking angular adjustments about two orthogonal axes. Requiring only simple machining and readily available parts, the design allows unrestricted access for incident and transmitted beams.

Accurate Wavelength Calibration of an Etalon-Tuned Dye Laser

A method to set accurately an etalon-tuned dye laser to any preselected wavelength within its lasing region is presented. The method involves a unique procedure to determine accurately the etalon thickness, so that the correct etalon order can be found for each wavelength and corresponding etalon setting. An equation relating the dial reading on the optical mount of the intracavity etalon to lasing wavelength is derived and evaluated for the Chromatix CMX-4 pulsed tunable dye laser. The procedure used to evaluate the equation parameters is described in detail. After establishing the value of all the equation parameters, a comparison is made between lasing wavelengths as predicted by the equation and as experimentally determined using laser-induced impedance changes to detect spectral lines in hollow cathode lamps. Agreement is found to be better than ±0.05 Å for all spectral lines used, with 68% of the predicted wavelengths within ±0.02 Å of their actual values. The micrometer drive for the birefringent filter, used in the CMX-4 to select an etalon order, is also calibrated using a quadratic polynominal equation, which gives predictions better than ±0.25 Å for all wavelengths tried in the regions of 5890 Å to 6050 Å and 6350 Å to 6720 Å, corresponding to the dyes R6G and R640, respectively.

Optical Beam Diagnostics on PEP

In designing the PEP optical diagnostics we have been able to build on the experience gained with SPEAR. Most of the problems at SPEAR could be traced to the optical diagnostic system being inside the tunnel. A machine shutdown is required for any maintenance or modification. This implies that in order to make such an instrument successful, a large engineering effort must be mounted to ensure 100% operation at startup. The functions that do not work at startup may never be made to work; this has happened at several machines. Experimental setups are likewise risky and time consuming. A point which has been borne out in both SPEAR and PEP is that the mechanical part of the instrument, the special vacuum chamber, the optical mounts, the alignment and adjustments, require approximately 60% of the effort and cost of the optical diagnostics. It is far better to economize on detectors and electronics than on mechanical and optical essentials.

Optical Properties in Anthracene Films

Abstract V. L. Broude et al.1 showed that optical contact mounting leads to a distortion of the optical properties of molecular crystals. The present paper compares and contrasts the true properties of freely mounted films of anthracene with those determined using the method of optical contact mounting. In addition, the temperature dependence of the polariton virtual mode absorption intensity has been determined for a freely mounted film and it is consistent with the mechanism of scattering (absorption) by acoustic phonons. From transmission and true absorption measurements with a very thin freely mounted film, it has been possible to determine for the first time the optical density profile of the surface exciton state previously observed by reflection and in fluorescence.

Métrologie de bancs d'optique. Application au cas particulier d'un spectromètre à réseau concave disposé selon le montage de Rowland

A new method is described for the alignment of the optical components in a Rowland concave grating spectrometer. The method is based on a system of optical mounts which have been specially designed...

Floating optical mount

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text John S. Rayside and William H. Fletcher, "Floating optical mount," Appl. Opt. 14, 2334-2335 (1975) Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article

Variable temperature sample cell and optical mount for laser Raman studies of adsorbed species

A sample cell and optical mount for use in laser Raman spectroscopic studies of adsorbed species at elevated temperatures is described. In situ Raman spectra of pyridine adsorbed on 60–120 mesh silica gel at room temperature, 75 °C, and 150 °C are reported. The cell has also been used in studies of other species adsorbed on silica, alumina, and platinum wire.

Optical components mount

A mount for optical components is described which allows for the rapid interchange of components in an optical system.