NASA/George C. Marshall Space Flight Center, Procurement Office, Marshall Space Flight Center, AL 35812

66 -- VIBRATION INSENSITIVE INSTANTANEOUS PHASE INTERFEROMETER (IPI) SOL 8-1-9-15-C3623 POC Glynda H. Meeks, Contract Specialist, Phone (256) 544-0422, Fax (256) 544-4400, Email glynda.meeks@msfc.nasa.gov -- Elaine W. Hamner, Contracting Officer, Phone (256) 544-0308, Fax (256) 544-9354, Email elaine.hamner@msfc.nasa.gov WEB: Click here for the latest information about this notice, http://nais.nasa.gov/EPS/MSFC/date.html#8-1-9-15-C3623. E-MAIL: Glynda H. Meeks, glynda.meeks@msfc.nasa.gov. NASA/MSFC plans to issue a Request for Quotation (RFQ) for a vibration insensitive Instantaneous Phase Interferometer (IPI). Requirements for this system are as follows: The total IPI-system shall consist of the following units: -- Interferometer mainframe -- Illuminator unit -- Remote control unit -- Control computer with frame grabber and control/interface electronics -- Software package OptiCode -- Set of divergers for sphere testing MAINFRAME The interferometer mainframe shall consist of a polarization-based Twyman-Green interferometer with the following features: -- The laser light from an external illuminator unit shall be fiber coupled into the mainframe. Thus the heat load of the laser source is removed from the interferometer and test setup. -- A polarization beam splitter cube (PBS) shall be used as the main interferometer beam splitter. The PBS-cube shall split the illuminating beam in test and reference beam. l/4-plates in both beams shall ensure close to 100% light efficiency for the beam recombination. -- A window at the output aperture shall seal the unit thus preventing contamination of the interior. -- The reflectivity of the reference mirror shall be optimized for best fringe contrast for coated and bare glass test surfaces. -- The tip/tilt of the reference mirror shall be finely adjusted (about 1 20 fringes) using the Remote Control Unit. -- In order to have additional control of the fringe phase piston during data acquisition, the reference mirror shall be mounted on a computer-controlled PZT-actuator. -- Using the remote control a beam block shall be able to be moved into the reference beam thus allowing to view the test beam only. This greatly facilitates the accurate definition of fiducials on the data maps. -- After recombination, the test beam and reference beam shall be able to be relayed by a high-accuracy afocal relay to the camera assembly. The relay shall be specially designed for low retrace errors when the slopes on the test surface lead to considerable fringe densities. -- A special assembly shall provide the instantaneous phase shift information in the camera image. This assembly shall allow extracting high-accuracy phase information from single camera frames. -- A digital camera with 1000x1000 pixels shall sense the interferograms. Its exposure time shall be set to very small value (about 1/10000 s). Thus rapid fringe motions due to vibrations shall essentially be frozen and sufficient contrast shall be maintained for a large range of vibrations. The camera signal shall be fed to the frame grabber in the control computer where the phase shift analysis and data processing shall take place. -- The pupil focus shall be adjusted from the Remote Control Unit. A range of 200mm in the collimated beam space outside the mainframe shall be accommodated. -- A twin-spot alignment mode shall be provided with a capture range of approximately 1 30. The switching between the align-mode and the view- or measurement-mode shall be done from the Remote Control Unit. -- A mainframe shall allow for adjusting the centration and tip/tilt of the whole mainframe unit to null out fringes. On a coarse scale this is much preferred over tilting the internal reference mirror, since otherwise the relay optics and other optics are not used on-axis, resulting in reduced measurement accuracy. -- The mainframe shall not contain a continuous zoom. Rather, a set of divergers with different f-numbers shall be part of the system. They shall attach directly to the flange of the main frame. This will result in improved imaging performance. ILLUMINATOR UNIT The illuminator unit shall contain the laser, fiber coupling optics, and the variable attenuator. A high power laser (> 5mW) at a wavelength of 632.8nm shall provide a long coherence beam. This beam shall be coupled into an optical fiber to be transferred to the mainframe unit. The variable attenuator in the Illuminator Unit shall allow for adjusting the light level for optimum exposure of the camera. The Illuminator unit shall be placed near the control computer and Remote Control Unit. REMOTE CONTROL UNIT The remote control unit shall be connected to the interferometer mainframe. With it the user shall be able to perform the following functions: -- Switch mode between Align and View -- Fine adjust x-tilt of reference mirror -- Fine adjust y-tilt of reference mirror -- Adjust pupil focus -- Turn reference beam block on and off (Note: The light level shall be adjusted directly at the Illuminator Unit.) CONTROL COMPUTER WITH ELECTRONICS The computer system shall be a state-of-the art Pentium-based system with 19" SVGA-monitor (projected is a Pentium III at more than 500MHz), running Windows. It shall host the frame grabber circuitry, as well as additional interface electronics to the mainframe. SOFTWARE The software package provided with the system shall be a derivative of a standard OptiCode package, with all its advanced data analysis, data manipulation, and graphics features. Special additions for the IPI shall include: -- High-resolution camera interface -- Advanced phase processing algorithms -- Special real-time display functions of the high-resolution video image -- Special near-real time display functions for the phase map modulo 2pi In addition, the VCR-mode software portion shall have the following features: -- User selectable data acquisition time intervals. Shortest interval is 67 ms. -- User defined playback time of graphics images after data analysis and processing -- Automatic processing of measurements acquired with "movie" of results stored. Length of movie dependent on size of data sets and hard disk space. -- VCR-function controls to fast-forward, rewind, freeze frame, slow motion, and backward play. The software shall run under Windows. SET OF DIVERGERS With the interferometer mainframe a set of divergers shall be provided. The divergers shall be mounted directly to the mounting flange on the interferometer mainframe. The standard set shall include divergerswith f-numbers f/1, f/2, f/4, and f/8. With that set a range of f-numbers from 1.0 to 16 is covered, where the test piece shall fill at least half the imager size of the mainframe. In addition, some extension tubes shall be provided to better match the locations of the focus points and the pupil images for the different divergers. SPECIFICATIONS BASIC SYSTEM Collimated output beam diameter: 15mm. Wavelength of operation: 632.8nm. Collimation of outgoing beam: l/4. Polarization of output beam: Circular. Focus range: +200mm to 0mm from aperture flange. Exposure time: 1/8000 s. Detector resolution: 1000x1000. Repeatability of PV1: l/500 surface. Repeatability of RMS2: l/2000 surface. RMS-Precision3: l/1000 surface. Uncalibrated accuracy4: l/20 PV surface. Detectable slope range: 1 250 fringes per full diameter, equivalent to 1 0.30 local surface slopes. Capture range align-mode: 1 30. Vibration environment (633nm): Exemplary single-frequency sinusoidal oscillations of axial position of test piece: < 0.5 mm PV at 1 Hz. < 50 mm PV at 10 Hz. < 5 mm PV at 100 Hz. < 0.5 mm PV at 1 kHz. < 0.2 mm PV for 2.5 kHz and higher. Size of mainframe: 500mm x 250mm x 150mm. Weight of mainframe: < 75 pounds. Remote control functions: Switch Align/View Adjustment of Pupil focus. Adjustment of Fine tip/tilt of reference mirror. Reference beam block on/off. Display of Align-image. Orientation for operation: Any. Temperature range for storage: 300F to 1500F. Temperature range of operation: 600F to 800F, thermal equilibrium required. SET OF DIVERGERS F-numbers: F/1.0, F/2, F/4, F/8. Wavefront distortion in single pass: Better l/8. DEFINITIONS FOR SPECIFICATIONS: 1: The repeatability of PV is defined as 1s of the distribution of PV-values of 20 repeated measurements under identical conditions, where each measurement consists of an average of 16 data sets. The PV-value is defined for a 98% cut-off in the histogram. The measurements are taken at a temperature of (7012)0F. 2: The repeatability of RMS is defined as 1s of thedistribution of RMS-values of 20 repeated measurements under identical conditions, where each measurement consists of an average of 16 data sets. The measurements are taken at a temperature of (7012)0F. 3: The RMS-precision is defined as average of the RMS-value of 19 difference maps of consecutive measurements taken under identical conditions, where each measurement consists of an average of 16 data sets. The measurements are taken at a temperature of (7012)0F. 4: The uncalibrated accuracy is defined as average PV-value of 20 repeated measurements of a high-quality flat (surface error < l/50 PV), where each measurement consists of an average of 16 data sets. The PV-value is defined for a 98% cut-off in the histogram. For the measurements the test set-up is adjusted for less than 10 fringes across the interferogram. The measurements are taken at a temperature of (7012)0F. This procurement is being conducted under the Simplified Acquisition Procedures (SAP). NASA/MSFC intends to purchase the items from ADEPhase Shift pursuant to FAR 6.302-1. ADE Phase Shift introduced the Simultaneous Phase Shifting Interferometer (SPSI) in 1992 and the technology has progressed in the areas of electronics, personal computers and camera technology. ADE Phase Shift will develop a second generation real-time interferometer capable of performing phase measurements under conditions of severe vibration and turbulence. The redesigned instrument will be developed based on the SPSI optical layout and enhanced with the latest technological improvements. It will be called Instantaneous Phase Interferometer (IPI). The Government intends to acquire a commercial item using FAR Part 12. Interested firms have 15 days from the publication of this synopsis to submit in writing to the identified point of contact, their qualifications/capabilities. Such qualifications/capabilities will be used solely for the purpose of determining whether or not to conduct this procurement on a competitive basis. Responses received after the 15 days or without the required information will be considered nonresponsive to the synopsis and will not be considered. A determination by the Government to not compete this proposed effort on a full and open competitive basis, based upon responses to this notice is solely within the discretion of the Government. Oral communications are not acceptable in response to this notice. All responsible sources may submit an offer which shall be considered by the agency. An Ombudsman has been appointed. See Internet Note "B". Any referenced notes can be viewed at the following URL: http://genesis.gsfc.nasa.gov/nasanote.html Posted 06/16/99 (D-SN343726). 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