1 December 2024

This optical characterization system is capable of performing both Raman and photoluminescence (PL) measurements across a broad spectral range of 200 to 2200 nm.

Photoluminescence (PL) is based on the principle that a material stimulated with light of a certain wavelength absorbs the energy and rises to a higher energy level, and the photons emitted while returning to the ground level are collected. The collected photons’ wavelength and intensity provide information about the material’s characteristic properties.

Raman Measurement: Laser light falling on the sample interacts with its molecules, and a very small number of photons are scattered back at different wavelengths. This phenomenon, known as Raman scattering, causes a shift in the frequency of the light, referred to as the Raman Shift. The Raman shift provides information about the types of chemical bonds in the sample, bond structures, bond lengths and angles, molecular vibrations and rotations, the phase state and chemical structure of the sample, stress and deformations in the samples, and the effects of environmental factors such as temperature and pressure on the sample.

• Motorized controlled compartment suitable for microscope and multi-laser system based photoluminescence – micro raman measurement systems
• Microscope body that can accommodate at least 7 objectives: available objectives: 10x (working distance min. 6.5 mm), 50x (working distance min. 8.2 mm), 100x (working distance min. 2.0 mm) vertical type microscope head for objective and cold head
• 25 mm diameter fused silica macro lens
• With 100x objective, 0.85NA and 532 nm TEM00 mode 500 nm beam spot size (spatial resolution)
• Narrow bandpass filters with a FWHM of at least 2 nm and a transmittance of at least 90% (T) for laser sources
• Motorized ND filter (Neutral Density Filter) to control laser power
• 5M pixel color camera, LED source part Koehler lighting system

 

• Laser light sources:
• Linearly polarized He-Cd Laser with 325 nm wavelength and 30 mW optical output power
• 532 nm wavelength diode-pumped solid-state laser with 100 mW optical output power
• 785 nm wavelength stabilized single-mode diode laser with 100 mW optical output power
• Mapping:
  • XYZ motorized table with a minimum movement range of 75 mm x 55 mm on the XY axes and a step resolution of at least 100 nm.
  • A desktop stage controller (Stage Step) that can be operated using the table control panel (stage joystick).
• Low-Temperature Unit:
• Two-stage Cold Head (50 Ohm resistance high power cartridge heater mounted)
• Helium (He) compressor
• Bellows type discharge valve and vacuum shut-off (shroud) safety pressure valve
• Silicon diode temperature sensor mounted on the cold finger and a silicon diode temperature sensor to measure the temperature at the location of the sample mounted on the sample holder
• For sample and cold head temperature control:
  • 24-bit digital resolution
  • Dual channel controller as 50 Watt and 1 Watt
  • PID loop control, “autotune” feature
  • Double multi temperature sensor input
  • Supports silicon diode, GaAlAs diode, platinum, germanium, carbon-glass, Cernox, RuO2, thermocouple sensors
  • Includes temperature curve data for DT-470, DT-500D, DT-670, PT-100, PT-1000, RX-102A, RX-202A type standard sensors and Type E, Type K, Type T, AuFe (0.07%)-Cr, AuFe 0.03% -Cr thermocouples in its memory
  • Heating rate between 0.1 K/min – 100 K/min
  • RS232, IEEE-488.2 (GPIB), and serial interface temperature control unit
• Low temperature unit vacuum system:
• At least 200 liters/minute maximum conveying at 50 Hz
• 2 × 10⁻³ mbar maximum total vacuum value
• 1000 mL oil capacity
• Vapor pressure tolerance of at least 32 mbar
• Able to provide vacuum of 3 × 10⁻² mbar with gas ballast and 2 × 10⁻³ mbar without gas ballast
• Two-stage rotary vane oil-filled mechanical pump

 

• Spectrograph and Detector Set:
• Spectrograph set:
• At least 750 mm focal length
• 3 cm⁻¹Raman shift resolution
• Raman shift pass band at 532 nm down to wavelengths smaller than 60 cm⁻¹
• Minimum f/9.8 aperture
• 300 gr/mm 500 nm crystallized grating (blaze grating) for 325 nm PL & wide-field Raman
• 600 gr/mm 1 µm crystallized grating for 785 nm Raman & NIR PL
• 1200 gr/mm 500 nm crystallized grating for Raman & PL

 

• Dedektör Seti:
• CCD Detector:
• 200 – 1050 nm spectral range
• 2000 x 256 pixel pixel format
• 15 µm x 15 µm pixel size
• 30 x 3.8 mm active area and 0.1e-/pix-second dark current value
• 142 spectra/second collection rate and 95% quantum efficiency
• InGaAs Detector:
• Thermoelectrically cooled InGaAs Array detector
• 1000 – 2200 nm spectral range
• 15 µm x 15 µm pixel size
• 2000 x 256 pixel pixel format
• 30 x 3.8 mm active area and 10.1e-/pix-hour dark current value 0.1e-/pix-second
• At least 70% quantum efficiency