...
Table of Contents:
| Table of Contents |
|---|
...
Introduction
...
The flat field fiber system (also known as the “wide flat” system) is used to project broadband light onto the main spectrometer CCDs. The projected light consists of a series of bands (one per echelle diffraction order), with each band being wider in cross-dispersion than the height of the orderlet stack. This allows one to calibrate the response of pixels both within the orderlets, and also between and outside the orderlets (which are normally not illuminated).
The system consists of a broadband source, a shutter, and a filter wheel (or in this case an aperture wheel). The aperture wheel is populated with various apertures, which are used to change the f/# of the beam leaving the output fiber (as shown below). This in turn changes the width of the bands on the main spectrometer CCDs and allows one to adjust the band overlap.
Note that a shutter is included to set the wide flat image exposure times. Within the aperture wheel there is also a blank port, which allows no light to pass. This should be in-beam whenever the wide flat system is not in use, to prevent stray light from entering the vacuum chamber from this system.
...
Relevant Devices
Descriptions | Qty | Source | Part Number | Notes |
|---|---|---|---|---|
Filter Wheel | 2 | Thorlabs | FW102C | RS-232 connectivity |
RS-232 to Ethernet Adapter | 1 | Lantronix | UDS2100 | This is the version with two serial ports (and standard 9-pin RS-232 connectors) |
Smaller Footprint Power Supply for Lantronix | 1 | Tri-Mag, LLC | Tri-Mag PN: L6R12H-120 DigiKey PN: 364-1264-ND | The stock Lantronix power supplies do not work well with the PDUs (as they block two extra outlets). KPF uses these replacement supplies since they only take up one PDU outlet. |
Broadband Source | 1 | Thorlabs | SLS201L |
...