The New Focus 1601 is an AC-coupled photoreceiver integrating a silicon PIN photodiode with a low-noise transimpedance amplifier for high-speed optical detection. Operating across the 320–1000 nm wavelength range with 1 GHz bandwidth and 400 ps rise time, it delivers peak responsivity of 0.5 A/W and noise-equivalent power of 31 pW/√Hz. Maximum conversion gain reaches 350 V/W with transimpedance gain to 700 V/A, supporting input optical power up to 10 mW and output drive up to 1 V peak-to-peak into 50 Ω loads. The device features a 0.4 mm silicon PIN detector, free-space optical input, and SMA output connector. AC coupling establishes a 30 kHz high-pass corner frequency; a DC bias monitor output operates at 20 kHz bandwidth with −10 V/mA transimpedance gain. RF shielding minimizes external interference. Standard 8-32 and M4 metric mounting threads accommodate flexible optical bench integration. The 1601 cascades with other 50 Ω amplifiers for system flexibility. Operating temperature range is 10–35 °C at humidity below 70%. Power requirements are ±15 VDC at 300 mA maximum; external power supply (not included) and included power cables Models 0923 and 0924 enable field deployment. Maximum photodiode current is 5 mA.
Technical Specifications
• Detector: Silicon PIN photodiode, 0.4 mm diameter
• Wavelength range: 320–1000 nm
• 3 dB bandwidth: 30 kHz to 1 GHz
• Rise time: 400 ps
• Peak responsivity: 0.5 A/W
• Maximum conversion gain: 350 V/W
• Maximum transimpedance gain: 700 V/A
• Noise-equivalent power: 31 pW/√Hz
• Maximum input optical power: 10 mW
• Maximum photodiode current: 5 mA
• Output impedance: 50 Ω
• Output drive capability: 1 V peak-to-peak into 50 Ω load
• AC high-pass corner frequency: 30 kHz
• DC bias monitor bandwidth: 20 kHz
• DC bias monitor transimpedance: −10 V/mA
• Power supply: ±15 VDC, 300 mA
• Operating temperature: 10–35 °C, < 70% RH
– Key Features
• Free-space optical input with 0.4 mm active area
• SMA output connector for 50 Ω systems
• Dual 8-32 and M4 metric mounting threads
• Integrated RF shielding
• DC bias monitor for photodiode health assessment
• AC-coupled architecture eliminates DC offset drift
• Cascadable with external 50 Ω amplifiers
– Typical Applications
• High-resolution spectroscopy
• Fiber-optic sensor systems
• Optical metrology
• Laser systems and beam characterization
• Imaging systems and photon detection
– Compatibility & Integration
The 1601 operates with external ±15 VDC power supplies purchased separately. Included power cables (Models 0923 and 0924) connect to standard laboratory supplies. SMA output connects directly to 50 Ω test equipment and signal chains. Metric M4 and imperial 8-32 threads enable mounting on standard optical benches. Cascading capability allows integration with additional transimpedance or buffer amplifiers.
