Related Experiment Video
Updated: Jun 13, 2026
10:17
20 mJ, 1 ps Yb:YAG Thin-disk Regenerative Amplifier
Published on: July 12, 2017
Summary
Amplified spontaneous emission (ASE) in Cassegrainian laser amplifiers creates unavoidable high-order components. These ASE paths can double the passes through the amplifier, impacting pulsed lasers more than continuous wave lasers.
Area of Science:
- Laser Physics
- Optical Engineering
Background:
- Multipass laser amplifiers with Cassegrainian telescope geometry are susceptible to amplified spontaneous emission (ASE).
- ASE components reflected from telescope mirrors are inherent to this amplifier design.
Purpose of the Study:
- To investigate all potential amplified spontaneous emission (ASE) paths in Cassegrainian multipass laser amplifiers.
- To analyze ASE components reflected from telescope mirrors and their impact on amplifier performance.
Main Methods:
- Modeling of amplified spontaneous emission (ASE) paths within a Cassegrainian telescope geometry.
- Analysis of ASE behavior in both ideal and near-Cassegrainian amplifier configurations.
Main Results:
- Identified unavoidable ASE components in Cassegrainian amplifiers.
- Demonstrated that certain ASE components undergo approximately twice the number of passes compared to the laser signal.
- Confirmed the presence of these high-order ASE components even in near-Cassegrainian configurations.
Conclusions:
- High-order ASE components in Cassegrainian amplifiers cannot be eliminated by adjusting mirror radii or separation.
- These ASE components are likely to have a more significant effect on pulsed laser systems than on continuous wave systems.
Related Concept Videos
01:16Cascaded Op Amps
Operational amplifiers (op-amps) are versatile electronic components that can be interconnected in a cascade - one after another in a linear sequence. This cascading is possible due to their infinite input resistance and zero output resistance, allowing them to maintain their input-output relationships even when connected in series.
In a cascaded system, each op-amp is referred to as a stage. The output of one stage drives the input of the subsequent stage. As the input signal passes through...
In a cascaded system, each op-amp is referred to as a stage. The output of one stage drives the input of the subsequent stage. As the input signal passes through...
01:23Small-Signal Analysis of MOSFET Amplifiers
In small-signal analysis, a MOSFET transistor amplifier acts as a linear amplifier when operating in its saturation region. The gate-to-source voltage (VGS) of the MOSFET is the sum of the DC biasing voltage and the small time-varying input signal. This combination sets up the operating point and modulates the drain current (ID) that flows from the drain to the source. When a small AC signal is superimposed on the DC bias voltage at the gate, the instantaneous drain current comprises three...
01:17MOSFET Amplifiers
The MOSFET, when operating in its active region, functions as a voltage-controlled current source. In this region, the gate-to-source voltage controls the drain current. This principle underlies the operation of the transconductance MOSFET amplifier. The output current is directed through a load resistor to convert this amplifier into a voltage amplifier. The output voltage is then obtained by subtracting the voltage drop across the load resistance from the supply voltage. This process results...
01:21Small-Signal Analysis of BJT Amplifiers
Small signal analysis is a fundamental approach used in electronics to understand how a Bipolar Junction Transistor (BJT) amplifier processes signals. In the active region, the BJT is designed for linear amplification. The transistor's behavior under these conditions is governed by its instantaneous base-emitter voltage VBE, a sum of the DC bias VBE, and a small AC signal VBE, resulting in the collector current iC. Here, the collector current has a DC component and an AC component.
01:22Amplifying Signals via Enzymatic Cascade
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
01:14BJT Amplifiers
Bipolar Junction Transistors (BJTs) are pivotal components in amplifier circuits, functioning as voltage-controlled current sources in their active region. This characteristic allows them to efficiently control the collector current through variations in the base-emitter voltage. Essentially, BJTs amplify power due to their ability to take a weak input signal and output a much stronger signal.
In BJT amplifier configurations, particularly in common-emitter setups, the transistor's role extends...
In BJT amplifier configurations, particularly in common-emitter setups, the transistor's role extends...