STM51004x/STM51005x Infineon Technologies Corporation, STM51004x/STM51005x Datasheet - Page 3

• Manufacturer Part Number: STM51004x/STM51005x
• Description: Laser Transmitters For Fiber Optic Applications (1300 And 1550 Nm)
• Manufacturer: Infineon Technologies Corporation

Description
Differences between a Fabry-Perot and a DFB Laserdiode
A conventional laser consists of an amplifying medium and two end mirrors. The cavity
is longer than one wavelength, and a standing wave is created. The number n of half
wavelengths is
laserdiode emits multi-longitudinal modes. Typically the laserdiode is 250 µm long. For
“standing wavelength” condition specified above is fulfilled. For a DFB-Laser a special
grating acts as a distributed filter allowing only one of the cavity’s longitudinal modes to
propagate. This can be described with a reduced oscillator length
of . For such a reduced oscillator length the standing wavelength condition will be
fulfilled for n
Figure 2
Data Sheet
= 1310 nm/1550 nm n is about 350. Therefore for many neighboring wavelengths the
Fabry-Perot Laserdiode
2 what means for only one wavelength.
n
=
2
4
0
0
L
-- -
. If L >> then we speak of a Fabry-Perot Laser because the
1
1
Wavelength
2
3
3
4
L ˜
5
which is in the range
STM51004x
STM51005x
Description
2001-06-01