1550 nm low-noise DFB laser
Koheron LD100 is a 1550 nm, low-noise, DFB laser with integrated current driver, photodetection and RF modulation. It works on a single 3.3V power supply and is designed to be mounted on a standard M6 metric breadboard. Laser current is adjusted with a precision trimmer from 0 to 55 mA. The LD100 features an AC-coupled modulation input for current modulation from 1 kHz up to 200 MHz. The integrated photodetection includes a transimpedance amplifier with a gain of 510 V/A and 100 MHz bandwidth. The LD100 has a typical spectral linewidth of 3 MHz.
Resources
Specifications
| LD100 | |
|---|---|
| Wavelength | 1550 nm |
| Supply voltage | 3.3 V to 15 V |
| Adjustable setpoint | 0 V to 2 V |
| Current setpoint | 33.2 mA/V |
| Current limit | 55 mA |
| Optical power(30 mA current) | 3 mW |
| Optical isolation | 30 dB |
| Spectral linewidth | typ. 3 MHz, ≤ 8 MHz |
| Photodetection bandwidth | 100 MHz |
| Photodetection transimpedance gain | -510 V/A |
| Photodetection output impedance | 50 Ω |
| Fiber output | 1 m SM fiber with FC/APC connector |
| Outputs | SMA for modulation and photodetection |
| Mechanical details | Compatible with M6 metric breadboards (25 mm spacing) |
Functional diagram
Characterization
Relative intensity noise
We characterized the laser relative intensity noise (RIN) for different operating currents. In all measurements, the same optical power (1 mW) was sent to the photodetector to maintain the same shot-noise floor.
The RIN decreases with increasing operating current. At 50 mA, the laser is shot-noise limited down to 50 kHz (1 dB excess noise).
Spectral linewidth
We measured the LD100 spectral linewidth using the self-homodyne method with a 10 km fiber delay. The figure below shows the power spectral density of the interference signal:
Linewidth is about 3.2 MHz at 30 mA and 2.4 MHz at 50 mA.
