Near-Infrared Single-Photon Detection Features 25% Efficiency
Geneva, Switzerland — The latest addition to id Quantique's line of single photon counters will be demonstrated in January 2007 at the BIOS and Photonics West exhibitions in San Jose, California. Users will now have the possibility to adjust the quantum detection efficiency to optimize performance.
The id201, id Quantique's newest product, offers the possibility to adjust the bias voltage, which controls the detection efficiency of the detector. Four preset values are available — 10%, 15%, 20% and 25%. Calibration is done at 1550nm. With a 25% detection efficiency, the id201 is the world's most sensitive near-infrared single-photon detection product, according to id Quantique. Alternatively, users can also select a mode where they can smoothly scan the bias voltage. The module covers the range between 900nm and 1700nm. The id201, like all single-photon detectors based on an InGaAs/InP avalanche photodiode, works in gated mode. A voltage pulse is applied on the photodiode to reverse bias it and activate it. Users can choose between five different gate widths (2.5ns, 5ns 20ns, 50 ns and 100ns). The id201 is said to be the only detector of its kind to offer short as well as long gate width. In order to give them full flexibility, id Quantique also added a feature allowing to scan the gate width continuously between 0 and 20ns.
The maximum trigger frequency has been increased from 4 MHz to 10MHz. The electronics also performs active quenching after avalanche sensing in order to maintain afterpulsing levels low, even at long gate widths. For further afterpulsing reduction, a deadtime feature can be used to blank gates for a certain time after an avalanche. With the adjustable delay, which allows to move the bias gate by up to 25ns in steps of 100ps, synchronization with the optical signal is a piece of cake.
The avalanche photodiode used at the heart of the id201 meets the most stringent reliability criteria (Telcordia GR-468-Core). It is available with a single-mode (SMF28) or multimode (50/125ms step index) fiber optical input. The module further includes internal counters as well as a display to monitor their values. With its RS-232 interface, which allows to remotely control the parameters of the module and to perform data acquisition, id Quantique describes the id201 as the world's most versatile single-photon detection module. Applications include quantum optics, quantum cryptography, fiber optic characterization, spectroscopy, single photon source characterization, eye safe laser ranging (lidar) and failure analysis of electronic circuits.
SOURCE: id Quantique