Linear Optical Resonator
Ring Resonator
EDF - Erbium Doped Fiber
WDM Coupler
Optical Pumping
Linear Fiber Laser
Laser Spiking
Lifetime of Excited State
Longitudinal Modes
InGaAs Photodetector
Mode Beat Frequency
LE-1200 Erbium doped Fiber Laser
The pump laser diode (LD) has a so called single mode fiber pigtail, terminated with a fiber connector and is directly connected with a fiber patch cable (PC) to the EDF fiber The light inside the fiber is partially reflected at each end face due to Fresnel reflections. Despite the low reflectivity of 4% laser oscillation is built up between the two end faces of the EDF due to the high gain. A collimator (CO) with short focal length forms an almost parallel beam and an InGaAs photodetector (PD) is used to detect the emission of the fiber The interference filter (IF) is mounted to an adjustment holder and passes only the 1.55 µm radiation. With its front face reflectivity of about 10% it serves also as an external cavity mirror to study the effect of a coupled optical cavity. The pump laser diode is connected to a controller (LD) with adjustable injection current and modulation. This allows to study the amplified spontaneous emission (ASE) below and above the laser threshold. By using the modulation of the injection current the lifetime of the excited state as well as impressive laser spiking is displayed and measured on an oscilloscope (OS). In the ring laser setup, the pump radiation is injected by a wavelength division multiplexer (WDM) into the ring structure which consists out of the EDF, a 4 port fiber coupler and an optical diode or just a fiber patch cable. The optical diode is used to force the ring laser either to the clockwise (cw) or counter clockwise (CCW) operation. Exchanging the optical diode against a fiber the ring laser oscillates in both directions. The 4 port fiber coupler is used to extract about 10% of the internal power of the cw and ccw ring laser mode for measurement purposes. Including the optical diode into the ring structures only cw or ccw oscillation occurs. By using an electronic spectrum analyser the beat frequency of the longitudinal ring resonator modes is measured and set into relation to the resonator length for the 2, 4 or 8 m long EDF.
A. Linear Fiber Laser
B. Fiber Ring Laser
Item | Code | Qty. | Description |
---|---|---|---|
1 | CA-0070 | 1 | NIR Laser viewing card 980 nm and 1.5µm |
2 | CA-0450 | 1 | BNC connection cable 1 m |
3 | DC-0040 | 1 | Diode laser controller MK1 |
4 | DC-0160 | 1 | InGaAs Photodetector with connection leads |
5 | DC-0380 | 1 | Photodetector Junction Box ZB1 |
6 | MM-0020 | 2 | Mounting plate C25 on carrier MG20 |
7 | MM-0440 | 1 | Kinematic mount ø25.4 mm on MG20, left |
8 | MP-0150 | 2 | Optical Bench MG-65, 500 mm |
9 | OC-0430 | 1 | Fiber jacket in C25 mount |
10 | OC-0758 | 1 | Laser line filter 980 nm in C25 mount |
11 | OC-0760 | 1 | Laser line filter 1550 nm in C25 mount |
12 | OC-2010 | 2 | ST/ST SM Fiber patch cable, length 0.25 m |
13 | OC-2100 | 1 | SM Fiber collimator |
14 | OC-2200 | 1 | Erbium doped fiber unit, ST terminated 1.5 m |
15 | OM-0540 | 1 | Diode laser module 980 nm, ST fiber connector |
16 | UM-LE12 | 1 | Manual Fiber Laser |
Required Option (order separately) | |||
17 | CA-0200 | 1 | Oscilloscope 100 MHz digital, two channel |
Option (order separately) | |||
18 | CA-0210 | 1 | Spectrum Analyzer 100 kHz - 500 MHz |
19 | LE-1240 | 1 | Fiber Ring Laser Extension |
20 | OC-2210 | 1 | Erbium doped fiber unit, ST terminated 4.0 m |
21 | OC-2220 | 1 | Erbium doped fiber unit, ST terminated, length 8 m |
22 | OC-2230 | 1 | Erbium doped fiber unit, ST terminated, length 16 m |