CCD Primer

Binning
Bracket Pulsing
CCD Grading
Cosmic Rays
Dark Current
Deep Depletion CCD
Detection Modes
Dual Capacity Mode
Dual Readout Mode
Dynamic Range
Etaloning in CCDs
eXcelon CCD-EMCCD
UV Extension
Fiber Optics
Flat Fielding
Full Well Capacity
Gain
Image Calibration
Imager Architectures
Image Intensifiers
ITO CCD
Kinetics Mode
Linearity
Matching Resolution
MPP Mode
Noise Sources
On-chip Multiplication Gain
Open Poly CCD
Optical Window
PVCAM
Quantum Efficiency
Readout vs Frame Rate
Reducing Dark Current
Saturation/ Blooming
Signal to Noise Calculator
Signal to Noise Ratio
Spurious Charge
XP Cooling

 

Deep Depletion CCD

NIR detection with regular CCDs can be quite challenging, especially for low-light applications, for the following reasons

  • 1. The silicon materials that CCDs are made becomes increasingly transparent in the NIR, which reduces the QE.
  • 2. Back-illuminated CCDs with high QE experience etaloning in the NIR range. The solution is the eXcelon CCD.
  • 3. Spectra and images taken in NIR suffer from thermal background noise in comparison to UV-VIS spectral range.

Deep Depletion CCDs (High-Resistance Silicon Substrate CCDs)
Deep depletion CCDs were specially designed for NIR applications which use a material called "epitaxial silicon, comprised of high-resistance silicon with a highly doped substrate. Epitaxial silicon minimizes the distance in which the charge generated by photons can diffuse without being counted as a signal. Princeton Instruments offers thermo-electric (TE) and liquid nitrogen (LN) cooled deep depletion detectors. Because Back-illuminated Deep depletion CCDs cannot be made with an MPP mode, they have a higher dark current. As a result, the half hour rule of thumb cannot be used. Instead, TE-cooled devices should be chosen if the typical exposure time expected for the application is below half a minute. An LN-cooled device should be chosen as an alternative. Princeton Instruments offers multiple spectroscopy and imaging detectors fabricated in deep depletion technology. They are based on PIXIS and SPEC-10 platforms and utilize 100*1340, 400*1340 , 256*1024 and 1024*1024 CCD formats. Current Back-illuminated Deep depleted CCDs, such as the PIXIS /400BR, offers up to 35% QE at 1000 nm, which is especially beneficial for such critical applications like NIR Raman spectroscopy.

Deep Depletion Technology

Conventional back-illuminated CCD and the NIR optimized deep depletion CCD

Advantages of Deep depletion CCDs:

  • Ability to probe materials and biological tissues at deeper depths
  • Easy discrimination of NIR fluorescence from the tissue auto-fluorescence
  • Increased availability of economical NIR illumination sources such as NIR lasers
  • Development of a new class of stable, NIR fluorescent probes
  • Increased interest in research areas such as Bose Einstein Condensate (BEC
  • Astronomical imaging (especially solar research) in NIR region
  • Absolute highest QE in the NIR
  • Tailored for etaloning elimination
  • Special NIR optimized antireflective coating
  • Specially treated back surface structure to further break up etaloning