DTMc300 Double Monochromator
Monochromator Configurations
Diffraction Gratings
A range of gratings are available depending on the spectral range of consideration, with up to three diffraction gratings mounted to each turret of the DTMc300.
| Grating | Line density (g/mm) | Grating type & Blaze wavelength | Maximum wavelength range (nm) |
|---|---|---|---|
| GA-T324R0U25 | 2400 | Plane ruled, 250nm blaze | 200-600 |
| 2400 | Plane holographic, 250nm blaze | 200-600 | |
| GA-T324H0U3 | 2400 | Plane ruled, 300nm blaze | 200-600 |
| 1800 | Plane holographic, 250nm blaze | 250-900 | |
| GA-T318R0U4 | 1800 | Plane ruled, 400nm blaze | 250-900 |
| 1800 | Plane ruled, 500nm blaze | 250-900 | |
| GA-T312H0U25 | 1200 | Plane holographic, 250nm blaze | 300-1,200 |
| GA-T312R0U4 | 1200 | Plane ruled, 400nm blaze | 300-1,200 |
| 1200 | Plane ruled, 500nm blaze | 300-1,200 | |
| 1200 | Plane ruled, 750nm blaze | 300-1,200 | |
| GA-T312R0U9 | 1200 | Plane ruled, 900nm blaze | 300-1,200 |
| GA-T312R1U0 | 1200 | Plane ruled, 1µm blaze | 300-1,200 |
| 830 | Plane ruled, 1.2µm blaze | 600-1,800 | |
| GA-T306R1U0 | 600 | Plane ruled, 1µm blaze | 800-2,500 |
| GA-T306R1U25 | 600 | Plane ruled, 1.25µm blaze | 800-2,500 |
| 600 | Plane ruled, 1.6µm blaze | 800-2,500 | |
| GA-T306R1U9 | 600 | Plane ruled, 1.9µm blaze | 800-2,500 |
| GA-T306R2U16 | 600 | Plane ruled, 2.16µm blaze | 800-2,500 |
| GA-T304R1U6 | 400 | Plane ruled, 1.6µm blaze | 1,000-3,000 |
| 300 | Plane ruled, 3µm blaze | 1,500-5,500 | |
| GA-T303R4U0 | 300 | Plane ruled, 4µm blaze | 1,500-5,500 |
| GA-T3015R4U0-AU | 150 | Plane ruled, 4µm blaze. Gold coated. | 3,000-10,000 |
| GA-T3015R6U0-AU | 150 | Plane ruled, 6µm blaze. Gold coated. | 3,000-10,000 |
| GA-T301R9U0-AU | 100 | Plane ruled, 9µm blaze. Gold coated. | 4,500-16,000 |
| GA-T30075R10U0-AU | 75 | Plane ruled, 10µm blaze. Gold coated. | 6,000-20,000 |
| GA-T30075R12U0-AU | 75 | Plane ruled, 12µm blaze. Gold coated. | 6,000-20,000 |
| GA-T3005R18U0-AU | 50 | Plane ruled, 18µm blaze. Gold coated. | 9,000-30,000 |
| GA-T3005R19U5-AU | 50 | Plane ruled, 19.5µm blaze. Gold coated. | 9,000-30,000 |
Slits
| Slit type | Features |
| Fixed slits (FSS) | - Manually controlled - Spring leaf to ensure the correct placement of the slit |
| Micrometer variable slits (VSS) | - Manually controlled - Bi-lateral slits - Variable from 10µm to 10mm |
| Motorised variable slits (MVSS) | - PC control via USB - Driven via internal monochromator electronics or external MAC electronics bin - Comprising stepping motor driven bi-lateral slits - Variable from 10µm to 10mm |
Filters
An order sorting filter wheel is located inside the entrance port of the monochromator, fitted with 6 or 8 filters selected for the spectral range of use.
When measuring below 400nm, no filters are required as the corresponding wavelength of the subsequent diffraction order is less than 200nm, which is naturally blocked by the atmosphere.
| Spectral range | Required OS filter |
|---|---|
| <400 nm | None |
| 400-700 nm | |
| 700-1250 nm | |
| 1250-2000 nm | |
| 2000-3600 nm | |
| 3.6-6 µm | |
| 6-10.5 µm | |
| 10.5-21 µm | |
| > 21 µm |
Further Options
| ND/ BP filters | Neutral density filters, used to attenuate optical signal level or band pass filters, to improve monochromator stray light performance, may be mounted in the filter wheel. |
| Purge ports | Purge ports fitted to monochromator to allow purging with nitrogen to remove atmospheric absorbants which absorb in the UV (<200nm) and IR (Various absorption bands). |
| Toroidal mirrors | Toroidal mirrors spherical mirrors replaced with toroidal mirrors for imaging applications. |
| Turret-mirror | A mirror may be fitted on a free location on the turret for the purposes of relating un-diffracted light to the exit port. |
| 418-INT | 418 optical chopper mounted behind the entrance slit. |
| Interchangeable turrets | For applications where very wide spectral range or regional optimisation is required, an interchangeable turret is available allowing the exchange of groups of three diffraction gratings to cover different spectral regions. In this case, the stepping motor in this case drives a platform to which is attached the grating assembly. |
| Shutter | Solenoid-based shutter for timed exposure applications. |