Intensified CCD (ICCD) 相機結合了增強器與 CCD 感測器。由於增強器的電子倍增功能,ICCD成為弱光或單光子應用的最佳選擇。它們也是需要少於納秒曝光時間應用的理想選擇,例如雷射誘導擊穿光譜 (LIBS) 或螢光壽命成像顯微鏡 (FLIM),因為增強器能夠快速關閉快門,同時仍將檢測到的任何光子轉換為光電子。
增強器由三個組件組成;光電陰極 (Photocathode)、微通道板 (MCP) 和沈積在光纖上的螢光屏 (Phosphor)。光電陰極位於石英窗後面,將入射光子轉換為電子。電子通過受控的電壓增加將這些電子加速到 MCP。 MCP 將每個光電子轉換為電子雲,然後電子雲傳播擊中螢光屏轉成可見光光子,再進入光纖並由 CCD 檢測到。由於入射光電子在 MCP 內倍增,因此 ICCD 探測器具有高靈敏度及單光子檢測能力。
由於增強器兩端由電壓受控,ICCD 探測器具有超高的快門速度。如果控制電壓反向,光電子會加速朝向光電陰極而不是 MCP,這可以防止任何光子通過增強器到達 CCD,這個過程被稱為門控 (gating)。PI-MAX4 ICCD 擁有 <500 pico-second門控。
emICCD 結合了 ICCD 和 EMCCD 技術的優點,由於 emICCD 能夠通過兩個獨立增益過程(增強器和電子倍增器)放大信號。它們能夠同時使用兩種增益機制。因此實現了最大增益,應用於低光和單光子成像具有最高靈敏度。
這種增益組合還消除了 ICCD 中常見的非線性。 ICCD 的非線性是由於 MCP 通道的飽和而產生的。這會影響 ICCD 的動態範圍,並可能改變定量測量。這種飽和與高增益有關,因此必須使用低增益以獲得更線性的響應。由於 emICCD 可利用兩個增益過程,因此可以降低 ICCD 組件的增益,而可以增加 EMCCD 組件的增益,以補償 MCP 的任何放大損失。
由於emICCD 探測器也集成了門控,因此它們能夠在高速運行的同時仍保持靈敏度、線性度和動態範圍的增加。這使得它們最適合捕獲任何動態影像和光譜應用。
ICCD & emICCD Cameras
The PI-MAX 4 delivers ultra-fast <500 psec gating without sacrificing quantum efficiency thanks to SuperHV – the latest in high-voltage gating technology. Degradation of the QE of the photocathode is avoided as intensifiers with metal-grid underlay are not used.
The PI-MAX 4 is calibrated for true optical full width at half maximum, delivering high temporal resolution for effective background discrimination.
The PI-MAX 4 achieves video frame rate at full resolution and >300 fps with reduced resolution and binning. In spectroscopy mode, it delivers >10, 000 spectra per second with sustained frame rate.
The PI-MAX 4 has the ability to capture a gated image or spectrum for every pulse from high-repetition-rate lasers.
Taking advantage of interline CCD architecture, the PI-MAX 4: 1024i is able to capture two full-resolution images with a less than 2 μsec inter-frame time.
This feature is especially useful for for particle imaging velocimetry or for real-time background/referencing where capturing two full-resolution images in a short frame time is required.
Controlling the intensifier gating is easy with the PI-MAX 4’s built-in precision timing generator, controlling gate widths and delays in 10 psec steps.
Not only can gate widths and delays be controlled, but SyncMASTER is able to synchronize the camera with a variety of external equipment, such as pulsed lasers.
Powerful and intuitive software with built-in math engine allows for the complete control of cameras and spectrographs, with real-time image analysis and spectral data.
LightField software provides seamless integration of hardware controls and direct data acquisition into programmes such as National Instruments’ LabVIEW® and MathWorks’ MATLAB®. This software also fully supports IntelliCal automated wavelength and intensity calibration.
The PI-MAX4 can also be fully controlled by PICAM SDK, eliminating any overhead that can occur when communicating through other development environments.
Intensifier gating repetition rate | 1 MHz |
---|---|
Gating | Down to <500 psec |
Supported interfaces | GigE |
Dark Current | ≤ 2.5 e-/p/sec |