ZOLIX DPe22 Pyroelectric Detector

Overview

The ZOLIX DPe22 is a room-temperature pyroelectric detector engineered for reliable, cost-effective infrared detection in spectroscopic applications. Unlike cryogenically cooled photodetectors, the DPe22 operates without active cooling—eliminating thermal management complexity and operational overhead while maintaining stable responsivity across the broad spectral range of 500 nm to 22 µm. Its sensing element is fabricated from lithium tantalate doped with gallium and strontium (LATGS), a material selected for its high pyroelectric coefficient, low dielectric loss, and mechanical robustness under repeated thermal cycling. The detector leverages the pyroelectric effect: incident modulated IR radiation induces transient temperature changes in the LATGS crystal, generating surface charge proportional to the rate of temperature change. This principle necessitates optical modulation—typically at ~70 Hz—to produce measurable AC output, making the DPe22 inherently compatible with lock-in amplification architectures for noise suppression and signal recovery.

Key Features

• Room-temperature operation—no thermoelectric or liquid-nitrogen cooling required
• Broadband spectral response from visible (500 nm) through mid-wave and long-wave infrared (up to 22 µm), limited only by window transmission
• Integrated low-noise voltage preamplifier optimized for pyroelectric signal conditioning
• Compact active area of 0.5 mm × 2 mm—designed for coupling with fiber outputs, monochromator slits, and FTIR beam paths
• ZnSe anti-reflection coated window as standard—provides >70% transmission from 0.6 µm to 16 µm; optional windows (e.g., KRS-5, CsI) available for extended IR coverage
• Positive-polarity voltage output with maximum amplitude of 4 V—compatible with standard ±5 V analog input stages
• Thermocouple-inspired mechanical layout—enhances thermal isolation and improves signal-to-noise ratio (SNR) stability

Sample Compatibility & Compliance

The DPe22 is intended for use in laboratory-grade spectroscopic systems including Fourier-transform infrared (FTIR) spectrometers, dispersive grating monochromators, and laser-based absorption setups. It interfaces seamlessly with commercial lock-in amplifiers such as the Stanford Research Systems SR830 or AMETEK Model 420, which provide the required reference-synchronized demodulation at ~70 Hz. While the detector itself does not carry regulatory certification, its design aligns with general-purpose instrumentation requirements under ISO/IEC 17025 for calibration traceability and supports GLP-compliant data acquisition when integrated into validated measurement chains. No hazardous materials are used in construction; RoHS compliance is maintained per ZOLIX manufacturing standards.

Software & Data Management

As a transducer-level component, the DPe22 does not include embedded firmware or digital interfaces. It delivers analog voltage output directly to external signal-processing hardware. When paired with lock-in amplifiers supporting GPIB, USB, or Ethernet connectivity, the detector’s output integrates into automated workflows via SCPI command sets or vendor-specific SDKs (e.g., SRS LabVIEW drivers, AMETEK Instrument Control Libraries). Full audit trails—including timestamped raw voltage traces, modulation frequency settings, and amplifier gain configurations—can be logged within compliant data acquisition platforms satisfying FDA 21 CFR Part 11 requirements when deployed in regulated environments.

Applications

• FTIR spectrometer detector replacement or auxiliary channel in dual-beam configurations
• Mid-IR gas-phase absorption spectroscopy (e.g., CO₂, CH₄, NOₓ monitoring)
• Material emissivity characterization in thermal emission studies
• Calibration reference for broadband IR source stability assessment
• Teaching laboratories—ideal for demonstrating pyroelectric physics and lock-in detection fundamentals
• Custom optical bench setups requiring wideband, non-cryogenic IR detection with minimal integration overhead

FAQ

Why must the DPe22 be operated with optical modulation?
Pyroelectric detectors respond only to *changes* in incident flux. A steady-state IR signal produces no output. Mechanical choppers or AOMs modulating the beam at ~70 Hz generate the necessary time-varying thermal gradient across the LATGS crystal.
Can I replace the ZnSe window with another material?
Yes—ZOLIX offers optional windows including KRS-5 (transmission to 40 µm) and CsI (to 55 µm). Custom window integration requires recalibration due to differential thermal mass and transmission profiles.
What is the recommended load impedance for the DPe22 output?
The integrated preamplifier is designed for ≥10 kΩ input impedance. Lower impedances may attenuate signal amplitude and degrade SNR.
Is the DPe22 suitable for pulsed laser detection?
It is not optimized for nanosecond- or microsecond-scale pulses. Its thermal time constant (~10–100 ms) limits response to quasi-continuous or low-repetition-rate modulated sources.
How does ambient temperature drift affect performance?
LATGS exhibits low pyroelectric coefficient temperature dependence (<0.1%/°C near 25°C). For measurements requiring <0.5% stability over 8-hour runs, enclosure temperature control within ±1°C is recommended.