Laser Coherence Control – Electronic Modulation Source for Laser Linewidth Broadening
- Stand-alone modulation source for ECDLs and DFB lasers
- Controlled linewidth broadening / coherence length reduction
- Coherence variation over more than three decades
- Adjustable linewidths up to GHz values (∼ 0.1 cm−1)
- Max. 28 dBm (0.6 W @ 50 Ohm) output
- For spectroscopy of Doppler-broadened lines
- For amplifier seeding, avoiding non-linear effects
TOPTICA's laser coherence control module LCC is a stand-alone module designed to broaden the spectral profile of external-cavity or distributed feedback (DFB) diode lasers. Via a dedicated current modulation scheme, the linewidth of an ECDL or DFB laser is augmented, while its tuning properties are preserved. This allows the researcher to tailor the coherence length of a his laser to any value between 100 m and a few cm.
Technical Information
Technical Information
| Concept | Stand-alone modulation source with separate power supply |
|---|---|
| Maximum power | 0.6 W (= 28 dBm) at 50 Ω |
| Attenuation | Adjustable via dip switch board, 0 .. -61 dB |
| Output bandwidth | 10 .. 200 MHz |
| Allowed voltage standing wave ratio (VSWR) at output | 1 .. ∞ |
| Connector | SMA |
For use with TOPTICA’s tunable diode lasers, an AC modulation input is required on the laser head (DL-MOD PCB).
Mode spectrum of a DL DFB laser. Blue: 1 MHz linewidth without modulation, red: linewidth broadening to 900 MHz using the LCC.
Options & Related Products
Options & Related Products
Related Products:
- Tunable diode lasers: DL pro, DL 100 / pro design, DL DFB, DL 100
- FPI 100: Scanning interferometer for laser mode analysis
- FALC 110 and DigiLock 110: Modules for laser linewidth narrowing
- iBeam smart: OEM diode laser with speckle elimination option
Technical Drawings
Applications
Applications
Applications of the LCC include
- Spectroscopy of molecular absorption lines,
- Spectroscopy of Doppler-broadened atomic absorption lines,
- Optical pumping of metastable Helium-3 atoms (1083 nm),
- Seeding of high-power fiber amplifiers, avoiding nonlinear effects.
The LCC complements TOPTICA’s portfolio of modules for laser linewidth manipulation: High-bandwidth regulators like FALC 110 and DigiLock 110 have been shown to achieve sub-Hertz linewidth values, whilst the LCC broadens the spectral profile to Gigahertz levels. The range of laser coherence control thus spans more than nine orders of magnitude (coherence length 130000 km .. 4 cm).
Application Note
