GaAs LASER LINEWIDTH MEASUREMENTS BY HETERODYNE DETECTION

1964 ◽  
Vol 5 (4) ◽  
pp. 72-74 ◽  
Author(s):  
J. W. Crowe ◽  
R. M. Craig
Keyword(s):  
Heterodyne Detection ◽  
Laser Linewidth ◽  
Gaas Laser

Influence of Laser Linewidth on Phase-OTDR System Based on Heterodyne Detection

2019 ◽  
Vol 37 (11) ◽  
pp. 2641-2647 ◽  
Author(s):  
Jiong Li ◽  
Zhitao Zhang ◽  
Jiulin Gan ◽  
Zhishen Zhang ◽  
Xiaobao Heng ◽  
...  
Keyword(s):  
Heterodyne Detection ◽  
Laser Linewidth

scholarly journals Effect of laser linewidth on the performance of heterodyne detection

2016 ◽  
Vol 65 (8) ◽  
pp. 084206
Author(s):  
Li Cheng-Qiang ◽  
Wang Ting-Feng ◽  
Zhang He-Yong ◽  
Xie Jing-Jiang ◽  
Liu Li-Sheng ◽  
...  
Keyword(s):  
Heterodyne Detection ◽  
Laser Linewidth

Scanned tip measurement of deep vertical facets on a flat surface: Measuring roughness on gaas laser waveguide mirrors

1993 ◽  
Vol 51 ◽  
pp. 532-533
Author(s):  
Chang Shen ◽  
Phil Fraundorf ◽  
Robert W. Harrick
Keyword(s):  
Integrated Circuits ◽  
Flat Surface ◽  
Scanning Force Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Optoelectronic Integrated Circuits ◽  
Laser Waveguide ◽  
Scanning Force ◽  
Gaas Laser

Monolithic integration of optoelectronic integrated circuits (OEIC) requires high quantity etched laser facets which prevent the developing of more-highly-integrated OEIC's. The causes of facet roughness are not well understood, and improvement of facet quality is hampered by the difficulty in measuring the surface roughness. There are several approaches to examining facet roughness qualitatively, such as scanning force microscopy (SFM), scanning tunneling microscopy (STM) and scanning electron microscopy (SEM). The challenge here is to allow more straightforward monitoring of deep vertical etched facets, without the need to cleave out test samples. In this presentation, we show air based STM and SFM images of vertical dry-etched laser facets, and discuss the image acquisition and roughness measurement processes. Our technique does not require precision cleaving. We use a traditional tip instead of the T shape tip used elsewhere to preventing “shower curtain” profiling of the sidewall. We tilt the sample about 30 to 50 degrees to avoid the curtain effect.

USE OF A CO2LASER AS A LOCAL OSCILLATOR FOR A 10 MICRON HETERODYNE DETECTION

1987 ◽  
Vol 48 (C7) ◽  
pp. C7-569-C7-571
Author(s):  
A. DELAHAIGUE ◽  
D. COURTOIS ◽  
C. THIEBEAUX ◽  
H. LE CORRE
Keyword(s):  
Local Oscillator ◽  
Heterodyne Detection

Generalized Heterodyne Configurations for Photo-induced Force Microscopy

2019 ◽  
Author(s):  
Le Wang ◽  
Devon Jakob ◽  
Haomin Wang ◽  
Alexis Apostolos ◽  
Marcos M. Pires ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Repetition Rate ◽  
Modulation Frequency ◽  
High Harmonic ◽  
Chemical Imaging ◽  
Heterodyne Detection ◽  
Force Microscopy ◽  
Wide Range ◽  
The Difference ◽  
Afm Cantilever

<div>Infrared chemical microscopy through mechanical probing of light-matter interactions by atomic force microscopy (AFM) bypasses the diffraction limit. One increasingly popular technique is photo-induced force microscopy (PiFM), which utilizes the mechanical heterodyne signal detection between cantilever mechanical resonant oscillations and the photo induced force from light-matter interaction. So far, photo induced force microscopy has been operated in only one heterodyne configuration. In this article, we generalize heterodyne configurations of photoinduced force microscopy by introducing two new schemes: harmonic heterodyne detection and sequential heterodyne detection. In harmonic heterodyne detection, the laser repetition rate matches integer fractions of the difference between the two mechanical resonant modes of the AFM cantilever. The high harmonic of the beating from the photothermal expansion mixes with the AFM cantilever oscillation to provide PiFM signal. In sequential heterodyne detection, the combination of the repetition rate of laser pulses and polarization modulation frequency matches the difference between two AFM mechanical modes, leading to detectable PiFM signals. These two generalized heterodyne configurations for photo induced force microscopy deliver new avenues for chemical imaging and broadband spectroscopy at ~10 nm spatial resolution. They are suitable for a wide range of heterogeneous materials across various disciplines: from structured polymer film, polaritonic boron nitride materials, to isolated bacterial peptidoglycan cell walls. The generalized heterodyne configurations introduce flexibility for the implementation of PiFM and related tapping mode AFM-IR, and provide possibilities for additional modulation channel in PiFM for targeted signal extraction with nanoscale spatial resolution.</div>

Determining laser linewidth parameter from Hopf bifurcation minimum in lasers subject to optical injection

2003 ◽  
Vol 39 (16) ◽  
pp. 1185 ◽  
Author(s):  
K.E. Chlouverakis ◽  
K.M. Al-Aswad ◽  
I.D. Henning ◽  
M.J. Adams
Keyword(s):  
Hopf Bifurcation ◽  
Optical Injection ◽  
Laser Linewidth
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