Reflectometers

Vorelco designed and built Dyn-Optics 262C Fiber Optic based Reflectometer

OPERATION

The Model 325R Reflectometer measures the specular reflectance at normal incidence from 350NM to 1100NM. The portion of the diffuse reflectance at 90° to the surface may also be measured.

FEATURES

Synchronous demodulated electronic system provides low noise operation so that the unit can operate in ambient light without affecting the accuracy.

Four decades of sensitivity

Wide band spectral sensitivity 350 to 1100NM (to 2.6 microns with infrared optics)

Four position filter cassette and choice of filters for selection of wavelengths.

Rigid metal test stand

Zero suppression to enable the operator to measure reflectance of the second surface of a test sample by depressing zero and essentially eliminating the known reflectance of the first surface.

Complete instruction manual

Two year warranty

INDUSTRIAL USERS AND APPLICATIONS

The Model 325R Reflectometer is employed by the follow¬ing industries to measure reflectance:

Wafer Fabricators to determine the quality of the silicon wafer from the surface reflectance and infer the etchability of aluminum coating from the reflectance

Photomask Manufacturers to verify low reflectance at exposing wavelengths

Optical Storage Disk Manufacturers to measure reflect¬ance at reading wavelengths

Compact Disk Industry to measure uniformity of coating

Optical Coating Processors to verify adherence to specifications

Display Equipment Manufacturers to measure the low reflectance of CRT faceplates and mounting panels

GENERAL

The Model 325R Reflectometer measures the specular reflectance at normal incidence from 350NM to 1100NM. The components of the diffuse reflectance 90° to the surface can be measured. The basic unit projects light down¬ward toward the stage where the test sample is located. The detector is located above the test sample in a position where the reflected light falls. The wavelengths are defined by four filters in a cassette. The instrument operates between 350NM and 1100NM. Wide band or photopic operation is also possible. The unit is housed in a rigid metal test stand that supports the optical system, test sample, electronics and display.

The 325R instrument consists of a sophisticated electro-optical detection and amplifier system that is the synchronously demodulated configura¬tion for maximum discrimination against spurious illumination and electronic noise. The reflectance is displayed on a 3-1/2 digit meter.

SPECIFICATIONS

Wavelength Range: 350NM to 1100NM; extendable to 2500NM with infrared detector option.

Wavelength Selection:

Measurements:

Incident Angle:

Range:

Accuracy:

Narrow bandpass filters in a four position filter cassette. Also operates with other filters such as wide band or photopic.

Specular and diffuse reflectance 0°

100% to 0% reflectance

HhO.5% compared against reference standard

Repeatability: ±0.2%

Substrate Stage: Fixed

Beam size: 20MM

Can be operated in full room light without affecting accuracy.

0-1 volt corresponding to 0 to 100% reflectance at rear of unit. With gain increased a decade, then output from 0 - 1 volt corresponds to 0 to 10%.

ORDERING INFORMATION

When ordering your 325R, please have your Purchase Order specify the following standard items:

Model 325R Reflectometer including the following standard items .... $6,225.00

Rigid table-top test stand with fixed stage including synchronously demodulated amplifier with 3-1/2 digit display and four decades of sensitivity.

Four position filter cassette and selection of filters from 350 to 1100NM of customer's choice. The filters are inserted into a cassette.

Set of calibration reflectors for 0%, 4%, and calibrated high reflectance aluminum samples.

Zero suppression to facilitate second surface reflectance measurements.

Quartz halogen chopped light source.

Detector for operation from 350NM to 1100NM.

Instruction Manual.

Two year warranty.

MODEL 325 T/R TRANSMISSOMETER / REFLECTOMETER for the measuring of transmission and/or reflection of samples

Four decades of sensitivity

Synchronously demodulated amplifier for accurate low noise operation

Wide band spectral sensitivity - 350 to 1000NM (to 2.6 microns with infrared optics)

Rigid metal test stand

Operates in full room light without adverse effects

Measures transmission and reflection simultaneously without changing components

Complete instruction manual

Two year warranty

Four position filter cassette for each channel i.e. transmission and reflection

Optional motor driven stage to enable the instrument to automatically move a sample to a specified number of positions for measurements

Optional electronics to enable the instrument to automatically make a measurement at each specific position and output the information to a computer or other device for data recording.

GENERAL

The 325 T/R Transmissometer / Reflectometer can measure reflectance and transmission simultaneously. The basic unit projects light downward toward the stage where the test sample is located. In the reflectance configuration, the detector is located above the test sample in a position where the reflected light falls. In the transmission mode, another detector is located below the stage and measures the transmitted beam. The electronics is essentially the same in reflection and transmission. The wavelengths are defined by filters in a cassette and enables the instrument to operate between 350NM and 1100NM. Wide band or photopic operation is also possible. The unit is housed in a rigid metal test stand that supports the optical system, test sample, electronics and display.

The 325 T/R instrumentation consists of a sophisticated electro-optical detection and amplifier system that is the synchronously demodulated configuration for maximum discrimination against spurious illumination and electronic noise. The transmission and reflectance is displayed on a 3-1/2 digit meter. Optical density is displayed in the density mode.

APPLICATIONS

The Reflectometer is employed in the following applications:

Reflectance of uncoated silicon wafers to certify surface finish.

Reflectance of coated silicon wafers to verify the aluminum.

Reflectance of photomasks to verify a low reflectance of short wavelengths.

Reflectance of optical storage disks to verify low reflection at infrared reading laser wavelengths.

Reflectance of compact disks to measure uniformity of coating.

Reflectance of witness samples of optical coating to verify adherence to specifications.

SPECIFICATIONS

350NM to 1100NM; can be extended to 2500NM with infrared detector option.

Narrow bandpass filters in a four position filter cassette. Can also operate with wide band or with photopic filters.

Specular and diffuse reflectance and transmission.

100% to 0% reflectance, 100% to 0% transmission

+0.5% compared against reference standard

Repeatability: Substrate Stage: 100% Adjustment: Incident Angle: Beam Size:

Operation Environment: Output: +0.2%

Fixed (Optional movable) Transmission and reflectance 0° 20MM or smaller diameter

Can be operated in full room light without affecting accuracy.

0-1 volt corresponding to 0 to 100% transmission or reflectance at rear of unit.

ORDERING INFORMATION

When ordering your 325 T/R,please have your Purchase Order specify the following standard items: $7,250.00

1 ea Model 325 T/R Transmissometer /

Reflectometer including the following standard items

Rigid test stand with fixed stage including amplifier with 3-1/2 digit display.

Two, four position filter cassettes: one for transmission and one for reflection.

Eight (8) filters from 350 to 1100NM. Customer's choice. Four filters are inserted in transmission cassette and four in the reflection cassette.

Set of calibration reflectors for 0%, 4%, and calibrated high reflectance aluminum samples.

Two year warranty. Instruction manu

Options

The 325 T/R can operate in both the reflection and transmission mode as described above or the instrument is also available in reflection or transmission only and the cost is: $6,225.

1 ea Model 325 T, Transmissometer 1 ea Model 325 R, Reflectometer $6,225.

An optical stage can be installed that is motor driven to any number of programmed positions. The stage can be stopped momentarily and a reflectance measurement recorded by a computer or other data recorder. This technique is employed in the inspection process for silicon wafers where the wafer is typically driven and reflectance measurements made at four positions around the circumference and at the center.

The Model 345 Specular / Diffuse Reflectometer enables the operator to measure specular and diffuse reflectance of samples on the stage. The specular reflectance can be measured at 0° or 15° angle of incidence. The diffuse reflectance measurement collects the reflected illumination within a +30° cone. The instrument operates with photopic spectral response or other wavelengths if desired. Zero suppression enables the operator to electronically cancel the first surface reflectance, and thereby measure the second surface reflectance only. The ratio of the diffuse to specular reflectance will uniquely quantize the polish of an optical surface. The instrument will detect finger prints on optical elements and will even detect a grain of sand on a clean glass surface.

Vorelco Refurbished Dyn-Optics Model 544 Multi-spectral Diffuse Reflectometer

MODEL 544 MULTISPECTRAL OPTICAL ANALYZER PERFORMS OPTICAL MEASUREMENTS ESSENTIAL TO VARIOUS INDUSTRIES

The integrating sphere is on the left and the electronic amplifier and waveband selector are on the right. The waveband of operation is shown on the left digital meter; the reflectance is shown on the right meter.

MEASUREMENTS

Model 544 measures:

Diffuse reflectance at various wavelength bands.

Total diffuse reflectance for various spec¬tral distributions of incident illumination.

Specular reflectance at various wave¬lengths.

Transmission at various wavebands of diffuse samples.

Transmission at various wavebands of non-diffusing samples.

APPLICATIONS

Model 544 measures spectral reflectance of diverse samples at various wavebands for evaluating:

Paint

Surface finish of polished or buffed metal

Cloth

Colored paper or printed paper

Photographs or negatives

Solar Collectors

Architectural windows

Solar Cells

CONFIGURATION

Model 544 employs an integrating sphere to collect the illumination diffusely reflected from samples. Filters define wavelength bands that are sensed by each of the four detectors. The signal from each detector is amplified and adjusted so that the instrument makes measurements for various spectral distribution of incident illumination.

The instrument contains a sophisticated electro-optical detection and amplifier system that is the synchronously demodulated configuration for maximum discrimination against spurious illumination and electronic noise.

SPECIFICATIONS

The standard Model 544 has the following specifications:

Wavelengths: Four bands including: blue, 400-500NM; green, 500-600NM; red and near IR, 600-1000NM; and IR, 1,000-2500NM.

Wavelength Five position rotary switch to

Selection: select waveband. Digital meter

indicates band of operation.

Measurements: Diffuse reflectance for each of the four bands

Total diffuse reflectance of solar spectrum

Average specular reflection over each of four bands

Average transmission over each of four bands

100% to 0% reflectance or transmission

Accuracy: ±1.0% compared against reference standard

Repeatability: +0.2% Incident Angle: 9°

INTEGRATING SPHERE

The instrument contains a sophisticated electro-optical detection and amplifier system that is the synchronously demodulated configuration for maximum discrimination against spurious illumi¬nation and electronic noise.

Beam Size: 10MM or smaller

Operation Environment:Operates in full room light without affecting accuracy.

Output: 0-1 volt corresponding to 1-100% reflectance or transmission at rear of unit.

OPTIONS

The standard Model 544 Multispectral Optical Analyzer utilizes four spectral bands for analysis of diffuse reflectance to solar illumination. The adjusted spectral response simulates the illumination from various sources or the photopic response of the eye. For better spectral resolution this instrument is upgraded to include eight wavelength bands.