ELSE cameras are available with both square-format imaging sensors and rectangular spectroscopy-oriented sensor formats. In the ELSEi series, four models are available covering square or near-square sensor resolutions from approximately 1k x 1k up to 4k x 4k. In the ELSEs series, we offer four rectangular sensor-format variants including 1k and 2k long-format sensors with smaller pixel counts in the shorter detector dimension, optimized for spectroscopy and spectrograph-based detection.

ELSEi models are available with usable pixel formats of 1024 x 1024 / 1056 x 1027, 2048 x 2052, 2048 x 2064 and 4096 x 4112 pixels. Available usable pixel formats for the ELSEs series of cameras start at 1024 x 127 for our most compact model, extending to 1024 x 255, and then to our 2k formats covering dimensions of 2048 x 264 and the wider-format 2048 x 515 pixel variant.

The active image area depends on the selected ELSEi or ELSEs model and describes the physical detector area available for imaging or spectroscopic applications. In the ELSEi series, active image areas range from 13.3 mm x 13.3 mm for the compact 1k1k model, corresponding to an approximate 18.8 mm diagonal, up to 61.4 mm x 61.4 mm for the large-format 4k4k model with an approximate 86.8 mm diagonal. The ELSEi 2k2k and 2k2k plus models provide intermediate active areas of 27.6 mm x 27.6 mm and 30.7 mm x 30.7 mm, with diagonals of approximately 39 mm and 43.4 mm, respectively.

The ELSEs series, targeted towards spectroscopy and spectrograph-based detection methods, follows a rectangular sensor format. The compact ELSEs 1k128 provides an active area of 26.6 mm x 3.3 mm, while the ELSEs 1k256 extends the shorter detector dimension to 6.7 mm. The 2k-format models provide active areas of 30.7 mm x 3.9 mm for the ELSEs 2k256 model and 27.6 mm x 6.9 mm for the wider-format ELSEs 2k512.

ELSE cameras are available with multiple CCD sensor types and anti-reflective coating options to support UV, visible, broadband and near-infrared detection. Depending on the selected ELSEi or ELSEs model, available sensor types include front-illuminated (FI), back-illuminated (BI), deep-depletion (DD), and for selected ELSEs configurations, open-electrode (OE) sensors.

The available coating options cover configurations optimized for UV sensitivity, visible and broadband detection, midband response, multiband detection and near-infrared sensitivity. This allows ELSE cameras to be matched to applications ranging from UV-sensitive measurements and high-QE visible detection to extended sensitivity in red/near-infrared spectroscopy or imaging.

As a general guide, UV-sensitive and back-illuminated options are used where short-wavelength response or high visible sensitivity is required, while deep-depletion configurations are selected for enhanced red/near-infrared sensitivity and fringe suppression. Our team will be happy to help identify the sensor and coating combination best matched to your spectral range, signal level and system requirements.

The sensitivity of ELSE cameras depends on the selected sensor type, sensor coating where applicable, spectral range and the required operating conditions of your application(s). Depending on the configuration, ELSE cameras can provide high quantum efficiency up to 98%, with sensor and coating options available for enhanced response in the UV, visible/broadband, multiband and near-infrared detection regimes.

Saturation behaviour will depend primarily on the full well capacity and gain setting of the camera, as well as exposure time required for your measurements and the incoming signal intensity. Across the ELSE range, full well capacity varies by model and sensor variant, from 75 ke⁻ for the ELSEs 2k256 camera, to 350 ke⁻ in our ELSEi 4k4k model and up to 700 ke⁻ for our highest-capacity ELSEs 1k deep-depletion configurations. Increased full well capacity allows stronger signals to be collected before saturation, while lower-noise readout and appropriate exposure settings are important for weak-signal measurements.

Overall, ELSE can be extensively configured to prioritise and/or balance maximum sensor sensitivity, high signal capacity, low noise, and extended UV or red/near-infrared response. Our team will be happy to help match the sensor format and sensor/coating configuration to your measurement requirements, and to advise on appropriate gain and readout settings for optimal camera operation.

ELSE cameras detect incoming photons with direct-detection scientific CCD sensors that convert light into electrical charge. Photons absorbed in the pixelated silicon sensor generate photoelectrons, which are collected with an accumulated charge proportional to the number of photons detected during sensor exposure. The conversion efficiency of incoming photons to collected photoelectrons is known as quantum efficiency and can be significantly enhanced, for example in cameras employing a back-illuminated (BI) sensor architecture.

The efficiency of photon-to-electron conversion can also be influenced by selection of an appropriate sensor coating for the target application, with ELSE coatings available for UV-sensitive, visible/broadband, multiband and near-infrared detection. Full well capacity is another important parameter and determines how much charge can be accumulated before the pixel saturation limit is reached; in certain camera configurations, this can be increased by opting for a deep-depletion sensor variant.

After exposure, the accumulated pixel charge is transferred through the CCD readout structure, to be converted into a voltage and then digitized by the camera electronics to produce an image or spectrum. Parameters like quantum efficiency, read noise, dark current, full well capacity and gain mode all work together to determine how sensitively photons can be detected, how much signal can be collected before pixel saturation takes place and how the measured charge is represented as digital counts.

ELSE users have several options available to optimize signal-to-noise ratio (SNR) and measurement resolution. Readout speed, exposure time, gain settings and pixel binning are all tunable parameters that can be balanced depending on the desired application and measurement requirements.

Readout speed and exposure time determine how fast data is acquired and for how long light is collected, directly influencing signal strength and read noise. Gain settings affect the scaling of the measurement signal, how collected charge is converted into digital counts, and thereby modifies system sensitivity and how much signal can be recorded before saturation.

Pixel binning refers to combining the charge from multiple adjacent pixels during readout, trading spatial or spectral resolution for increased collected signal per output (binned) pixel, and improved SNR. This can be a very useful strategy particularly in spectroscopy applications, since in a typical spectrograph setup only one axis carries spectral information, with the non-dispersive detector axis representing instead the height or width of the spectral signal.

In such a setup, vertical binning can be applied to sum the signal across the non-dispersive axis into a condensed spectrum, improving signal strength and SNR without losing wavelength information. ELSE cameras support fully flexible pixel binning, so pixel output can be controlled as needed for measurements on a case-by-case basis.

In cases of uncertainty, we will gladly support ELSE and greateyes customers to identify the right settings for specific measurements and conditions. Don’t hesitate to reach out!

ELSE cameras are designed to support ultra-deep thermoelectric cooling for low dark current and stable detector performance. Within the ELSEi series, the ELSEi 1k1k model is capable of cooling from -100°C to 20°C, while the ELSEi 2k2k, 2k2k plus and 4k4k models are specified from -90°C to 20°C. ELSEs models are capable across the board of cooling down to -100°C.

Deep cooling is particularly important for longer exposure times and low-signal measurements, where dark current can contribute to the detector noise floor. Depending on the selected model and application requirements, ELSE cameras can be supported by appropriate cooling configurations and optional cooling accessories for specific thermal and integration requirements.