Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Infrared (IR) Spectroscopy: Overview01:09

Infrared (IR) Spectroscopy: Overview

3.0K
When electromagnetic radiation passes through a material, atoms or molecules transition from a lower to a higher energy state by absorbing radiation corresponding to the energy difference between the two states. The absorption of infrared (IR) radiation causes transitions between vibrational energy levels in a molecule. Therefore, IR spectroscopy is a useful analytical tool for determining the molecular structure of molecules.
Different compounds display unique properties due to their...
3.0K
IR Absorption Frequency: Hybridization01:21

IR Absorption Frequency: Hybridization

827
Hydrocarbons such as alkanes, alkenes, and alkynes show characteristic C–H stretching absorption bands. These IR stretching frequencies depend on the hybridization of the involved carbon atom and can be explained in terms of the s character of each hybridized atomic orbital.
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that...
827
IR Spectrometers01:25

IR Spectrometers

1.6K
There are two main infrared (IR) spectrophotometers: dispersive IR spectrometers and Fourier transform infrared (FTIR) spectrometers. In a dispersive IR spectrometer, a beam of infrared radiation produced by a hot wire is divided into two parallel equal-intensity beams using mirrors. One beam passes through the sample, while another is a reference beam. The beams then move through the monochromator, which separates the radiations into a continuous spectrum of different frequencies. The...
1.6K
IR Spectrum01:19

IR Spectrum

1.4K
When infrared (IR) radiation passes through a molecule, the bonds stretch or bend by absorbing the radiation. This absorption creates the molecule's absorption spectrum, which is the plot of its percentage transmittance versus wavenumber.
Transmittance is defined as the ratio of the radiant power passing through a sample to that from the radiation's source. Multiplying the transmittance by 100 gives the percent transmittance (%T), which varies between 100% (no absorption) and 0%...
1.4K
IR Frequency Region: X–H Stretching01:24

IR Frequency Region: X–H Stretching

1.1K
In IR spectroscopy, signals produced by the X−H bonds (such as C−H, O−H, or N−H) can be observed in the frequency range of  2700–4000 cm–1. The C−H stretching vibration forms sharp bands in the region 2850–3000 cm–1. The presence of the O−H stretching vibration leads to the forming of an absorption band in the frequency range 3650–3200 cm−1. At the same time, N−H stretching can be confirmed by absorption bands in...
1.1K
IR Frequency Region: Fingerprint Region01:03

IR Frequency Region: Fingerprint Region

1.3K
IR spectra are divided into two main regions: the diagnostic region and the fingerprint region. The diagnostic region of the spectrum lies above 1500 cm−1. The absorptions resulting from single-bond vibrations of the N–H, C–H, and O–H stretch at higher wavenumbers and appear on the left side of the spectrum. The stretching absorptions of the C≡C and C≡N occur between 2100–2300 cm−1. In contrast, those arising from stretching absorptions of the...
1.3K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

High efficiency and responsivity universal silicon modulator and detector for the O-band.

Optics express·2026
Same author

Combining IR and Raman Spectroscopies for Enhanced Accuracy and Precision in the Determination of Lipid Composition in Liposomes.

Biomolecules·2026
Same author

Sustained poling-induced second-order optical nonlinearity in sodium-doped amorphous niobium oxide waveguides.

Scientific reports·2026
Same author

Effects of Sample Deposition Medium and Drying on Spectroscopic Quantification of Lipid Biomarkers in Respiratory Distress Syndrome.

Biosensors·2026
Same author

Polarization-independent narrow-band integrated add-drop filter for the short near-infrared wavelength range.

Optics letters·2026
Same author

Breaking the mid-infrared interconnection barrier: a robust bonding for high-power optics based on liquid-like chalcogenide glass.

Light, science & applications·2026

Related Experiment Video

Updated: Oct 14, 2025

Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing
10:42

Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing

Published on: March 22, 2019

6.4K

Broadband 2  ×  2 multimode interference coupler for mid-infrared wavelengths.

Callum J Stirling, Robert Halir, Alejandro Sánchez-Postigo

    Optics Letters
    |November 1, 2021
    PubMed
    Summary
    This summary is machine-generated.

    Researchers developed a subwavelength-structured multimode interference coupler for photonic integrated circuits. This new device doubles the operational bandwidth for mid-infrared sensing applications.

    More Related Videos

    Low-cost Custom Fabrication and Mode-locked Operation of an All-normal-dispersion Femtosecond Fiber Laser for Multiphoton Microscopy
    08:48

    Low-cost Custom Fabrication and Mode-locked Operation of an All-normal-dispersion Femtosecond Fiber Laser for Multiphoton Microscopy

    Published on: November 22, 2019

    7.7K
    Microwave Photonics Systems Based on Whispering-gallery-mode Resonators
    12:18

    Microwave Photonics Systems Based on Whispering-gallery-mode Resonators

    Published on: August 5, 2013

    17.1K

    Related Experiment Videos

    Last Updated: Oct 14, 2025

    Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing
    10:42

    Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing

    Published on: March 22, 2019

    6.4K
    Low-cost Custom Fabrication and Mode-locked Operation of an All-normal-dispersion Femtosecond Fiber Laser for Multiphoton Microscopy
    08:48

    Low-cost Custom Fabrication and Mode-locked Operation of an All-normal-dispersion Femtosecond Fiber Laser for Multiphoton Microscopy

    Published on: November 22, 2019

    7.7K
    Microwave Photonics Systems Based on Whispering-gallery-mode Resonators
    12:18

    Microwave Photonics Systems Based on Whispering-gallery-mode Resonators

    Published on: August 5, 2013

    17.1K

    Area of Science:

    • Photonics
    • Integrated Optics
    • Optical Sensing

    Background:

    • Beam splitters are essential for photonic integrated circuits, often using multimode interference (MMI) couplers.
    • Current MMI couplers have limited operational bandwidth, hindering mid-infrared (MIR) sensing applications.

    Purpose of the Study:

    • To experimentally demonstrate a novel subwavelength-structured 2x2 multimode interference coupler.
    • To enhance the operational bandwidth of MMI couplers for MIR applications.

    Main Methods:

    • Fabrication of a 2x2 multimode interference coupler utilizing subwavelength structuring.
    • Experimental characterization of the coupler's performance in the 3.1-3.7 µm wavelength range.

    Main Results:

    • Achieved high performance for the subwavelength-structured MMI coupler.
    • Demonstrated a bandwidth of 3.1-3.7 µm, covering a significant portion of the MIR range.
    • Doubled the operational bandwidth compared to conventional MMI coupler designs.

    Conclusions:

    • Subwavelength structuring is an effective method for enhancing MMI coupler bandwidth.
    • The developed coupler shows promise for advanced MIR photonic integrated circuit applications, particularly in sensing.