Product Brief 
Sales & Technical Support
Features
- Narrow-Linewidth Monolithic Design
- Rugged
- Ultra Compact
- High Modulation Amplitude
- Frequency Modulation Response
Applications
- Distributed Sensing Based on Rayleigh Scattering (DAS / C-OTDR / φ-OTDR / OFDR)
- Quantum Key Distribution (QKD)
- SATCOM
- Frequency Modulation Continuous Wave LiDAR (FMCW LiDAR)
- Doppler LiDAR & Vibrometry
- Brillouin Sensing (BOTDR)
- Radio Frequency over Fiber
- Precision Metrology
Resources
- Product Brief Product Brief
- White Paper – Rethinking Laser Performance White Paper – Rethinking Laser Performance
- App Note – DAS App Note – DAS
- Blog – Low Noise & Fast Modulation, Built for Lidar, and More Blog – Low Noise & Fast Modulation, Built for Lidar, and More
- Blog – Innovative DFB Laser Diode Blog – Innovative DFB Laser Diode
- Blog – DV-QKD Blog – DV-QKD
- Blog – QKD in Optical Comm Blog – QKD in Optical Comm
- News – Laser Focus World Award News – Laser Focus World Award
- Blog – Quantum Technologies Blog – Quantum Technologies
Webinar
A Narrow-Linewidth Distributed Feedback Laser Diode with Unique Frequency Modulation Response
Patrice Dionne
Product Line Manager
The LXM Narrow-Linewidth DFB Laser Module is based on indie’s proprietary laser diode technology. This single-frequency laser is available in both standard (LXM-S) and ultra-narrow models (LXM-U), reaching down to ﹤0.1 kHz linewidth. Ultra-low phase noise and fast frequency modulation properties make this laser unique and sets new standards in narrow linewidth lasers.
The LXM integrates a DFB laser diode, a low-noise current source and a high-stability temperature controller in a single, compact package. This semiconductor laser module is designed for seamless integration, high robustness and high reliability, which makes it the perfect choice for system integrators.
In addition to offering the lowest intrinsic linewidth in its category, the standard LXM-S features an intrinsically flat and high bandwidth FM response (magnitude and phase), making it an ideal laser source for frequency sweeping sensing applications such as FMCW LIDAR and OFDR distributed fiber sensing.
The ultra-narrow LXM-U also combines a frequency noise cancelation feedback system that provides unmatched performance without compromising the lasing mode stability, which explains its growing adoption in phase-sensitive sensing applications, quantum key distribution (QKD) and microwave/radio-frequency photonics.
Key Features and Benefits
Narrow-Linewidth Monolithic Design:
The LXM features typical 15 kHz instantaneous linewidth under direct drive and typical 0.05 kHz for the ultra-narrow linewidth model.
Rugged:
The LXM is a full semiconductor laser solution packaged in a rugged housing, providing a high tolerance to shocks and vibrations. The laser is operational over a temperature range of -20° C to 65° C.
Ultra Compact:
The LXM fits within a volume of 90 mm x 56 mm x 18 mm.
High Modulation Amplitude:
The LXM reaches a typical 3 GHz amplitude at 100 kHz modulation frequency (triangular waveform).
Frequency Modulation Response:
With its flat frequency modulation response, the LXM enhances frequency chirp linearity optimization and enables precise optical frequency and phase locking.
Comparative Scorecards
| LXM | Distributed Feedback Fiber Laser | Extended Cavity Semiconductor Laser | |
|---|---|---|---|
| Frequency Noise | Excellent | Very Good | Good |
| Relative Intensity Noise (RIN) | Excellent | Fair | Excellent |
| Optical Power | Excellent | Very Good | Fair |
| Immunity to Vibrations | Excellent | Fair | Fair |
| Brand/Reputation | Good | Good | Good |
| Reliability | Very Good | Very Good | Good |
| Service/Customer Support | Excellent | Very Good | Good |
| Price | $$ | $$$ | $$ |
| Overall Price-to-Performance Ratio | Excellent | Good | Good |
| Product Details | |
|---|---|
| Output Power | From 40 mW up to 70 mW |
| Wavelength | Selection of a single wavelength at 1515 nm or between 1540 nm and 1565 nm |
| Instantaneous Linewidth, Standard Module LXM-S | 15 kHz typical |
| Instantaneous Linewidth, Ultra-Narrow Module LXM-U | 0.05 kHz typical |
| Frequency Modulation Amplitude* *Limited to 200 MHz for the Ultra-Narrow Module | 3 GHz typical at 100 kHz modulation rate |
| Relative Intensity Noise at > 1 MHz | < -155 dB |