diodearraydetektorer

A diode array detector is an electronic device that consists of many photodiodes arranged in a linear or two‑dimensional grid. Each diode functions as a small sensor that converts incident photons into an electrical current. The array format allows simultaneous measurement of the light intensity at multiple spatial points, producing a digital scan of the light distribution.

The most common type is the single‑sided p‑i‑n array, where each pixel is a p‑i‑n photodiode fabricated on the same semiconductor substrate. The dark current and capacitance of each pixel are kept low, giving fast response times in the microsecond range and high signal‑to‑noise ratios. Some arrays include built‑in transimpedance amplifiers to improve linearity and dynamic range.

Diode array detectors are widely used in analytical instrumentation, particularly in compact spectrophotometers and fluorescence scanners. In mass spectrometry, linear arrays covering several millimeters can detect UV and chemiluminescent signals, enabling rapid chromatographic profiling without optical scanning. They also find use in x‑ray film replacement, near‑infrared surface inspection, and medical imaging of skin reflectance.

Key performance metrics are pixel pitch (often 25–50 µm), spectral responsivity (typically 400–800 nm for visible arrays), and noise equivalent power. Limitations include a narrower spectral range compared to CCDs or CMOS sensors and susceptibility to radiation damage in high‑energy photon environments. Despite these constraints, diode arrays remain popular for applications that demand fast, linear, and robust detection over a moderate dynamic range.