Laser-induced tunneling ionization underlies a broad class of strong-field phenomena in attosecond physics. A key quantity in this process is the transverse tunneling exit position, which influences both the phase of the continuum wave packet and the subsequent electron dynamics. In this work, we show that the intracycle interference between directly ionized electron wave packets provides a sensitive probe of the transverse tunneling exit position in molecules. By numerically solving the time-dependent Schrödinger equation for the aligned ${\mathrm{N}}_2$ molecule, we observe a pronounced, alignment-dependent asymmetry in the intracycle interference pattern of the photoelectron momentum distribution. Analysis based on adiabatic theory reveals that this asymmetry originates from the transverse shift of tunneling exit position. The exit position is reconstructed from the interference patterns with picometer-scale precision and is consistent with the result obtained from the electron density distribution of the molecular orbital.

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• Atomic & molecular processes in external fields
• Electronic structure of atoms & molecules
• Light-matter interaction
• Multiphoton or tunneling ionization & excitation